BrowserCheckPlugin throws exception when visiting login page with Firefox 3.6

When opening the cms login page, I see this:

[INFO] Started Jetty Server
CMS 2010-01-28 10:59:01,125 ERROR [org.hippoecm.frontend.plugin.impl.PluginFactory] java.lang.NumberFormatException: For input string: "6 ("
java.lang.reflect.InvocationTargetException
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
at java.lang.reflect.Constructor.newInstance(Constructor.java:513)
at org.hippoecm.frontend.plugin.impl.PluginFactory.createPlugin(PluginFactory.java:71)
at org.hippoecm.frontend.plugin.impl.PluginManager.start(PluginManager.java:84)
at org.hippoecm.frontend.plugin.impl.PluginContext.start(PluginContext.java:248)
at org.hippoecm.frontend.plugin.impl.ClusterControl.start(ClusterControl.java:112)
at org.hippoecm.frontend.Home.<init>(Home.java:111)
at org.hippoecm.frontend.Home.<init>(Home.java:64)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
at java.lang.reflect.Constructor.newInstance(Constructor.java:513)
at org.apache.wicket.session.DefaultPageFactory.newPage(DefaultPageFactory.java:149)
at org.apache.wicket.session.DefaultPageFactory.newPage(DefaultPageFactory.java:58)
at org.apache.wicket.request.target.component.BookmarkablePageRequestTarget.newPage(BookmarkablePageRequestTarget.java:262)
at org.apache.wicket.request.target.component.BookmarkablePageRequestTarget.getPage(BookmarkablePageRequestTarget.java:283)
at org.apache.wicket.request.target.component.BookmarkablePageRequestTarget.processEvents(BookmarkablePageRequestTarget.java:210)
at org.apache.wicket.request.AbstractRequestCycleProcessor.processEvents(AbstractRequestCycleProcessor.java:91)
at org.hippoecm.frontend.PluginRequestCycleProcessor.processEvents(PluginRequestCycleProcessor.java:31)
at org.apache.wicket.RequestCycle.processEventsAndRespond(RequestCycle.java:1175)
at org.apache.wicket.RequestCycle.step(RequestCycle.java:1252)
at org.apache.wicket.RequestCycle.steps(RequestCycle.java:1353)
at org.apache.wicket.RequestCycle.request(RequestCycle.java:493)
at org.apache.wicket.protocol.http.WicketFilter.doGet(WicketFilter.java:355)
at org.apache.wicket.protocol.http.WicketServlet.doGet(WicketServlet.java:124)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:707)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:820)
at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:511)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1166)
at org.hippoecm.frontend.plugins.login.ConcurrentLoginFilter.doFilter(ConcurrentLoginFilter.java:54)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:388)
at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216)
at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:182)
at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:765)
at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:418)
at org.mortbay.jetty.handler.ContextHandlerCollection.handle(ContextHandlerCollection.java:230)
at org.mortbay.jetty.handler.HandlerCollection.handle(HandlerCollection.java:114)
at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
at org.mortbay.jetty.Server.handle(Server.java:326)
at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:542)
at org.mortbay.jetty.HttpConnection$RequestHandler.headerComplete(HttpConnection.java:923)
at org.mortbay.jetty.HttpParser.parseNext(HttpParser.java:547)
at org.mortbay.jetty.HttpParser.parseAvailable(HttpParser.java:212)
at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:404)
at org.mortbay.io.nio.SelectChannelEndPoint.run(SelectChannelEndPoint.java:409)
at org.mortbay.thread.QueuedThreadPool$PoolThread.run(QueuedThreadPool.java:582)
Caused by: java.lang.NumberFormatException: For input string: "6 ("
at java.lang.NumberFormatException.forInputString(NumberFormatException.java:48)
at java.lang.Integer.parseInt(Integer.java:458)
at java.lang.Integer.parseInt(Integer.java:499)
at org.hippoecm.frontend.plugins.standards.behaviors.BrowserCheckPlugin$WicketBrowserInfo.parseMajorMinor(BrowserCheckPlugin.java:218)
at org.hippoecm.frontend.plugins.standards.behaviors.BrowserCheckPlugin$WicketBrowserInfo.setVersions(BrowserCheckPlugin.java:210)
at org.hippoecm.frontend.plugins.standards.behaviors.BrowserCheckPlugin$WicketBrowserInfo.<init>(BrowserCheckPlugin.java:187)
at org.hippoecm.frontend.plugins.standards.behaviors.BrowserCheckPlugin.bind(BrowserCheckPlugin.java:268)
at org.apache.wicket.Component.add(Component.java:929)
at org.hippoecm.frontend.service.render.AbstractRenderService$2.onServiceAdded(AbstractRenderService.java:207)
at org.hippoecm.frontend.service.render.AbstractRenderService$2.onServiceAdded(AbstractRenderService.java:193)
at org.hippoecm.frontend.service.ServiceTracker.addService(ServiceTracker.java:35)
at org.hippoecm.frontend.plugin.impl.PluginManager.internalRegisterService(PluginManager.java:250)
at org.hippoecm.frontend.plugin.impl.PluginManager.registerService(PluginManager.java:143)
at org.hippoecm.frontend.plugin.impl.PluginContext.registerService(PluginContext.java:171)
at org.hippoecm.frontend.plugins.standards.behaviors.BrowserCheckPlugin.<init>(BrowserCheckPlugin.java:260)
... 49 more
CMS 2010-01-28 10:59:01,296 ERROR [org.hippoecm.frontend.plugin.impl.PluginFactory] java.lang.NumberFormatException: For input string: "6 ("
Failed to instantiate plugin 'org.hippoecm.frontend.plugins.standards.behaviors.BrowserCheckPlugin' for id 'null'.
CMS 2010-01-28 10:59:36,421 INFO [org.hippoecm.frontend.model.JcrSessionModel] [127.0.0.1] Invalid login as user: admin
CMS 2010-01-28 10:59:36,421 ERROR [org.hippoecm.frontend.plugin.impl.PluginFactory] java.lang.NumberFormatException: For input string: "6 ("
java.lang.reflect.InvocationTargetException
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
at java.lang.reflect.Constructor.newInstance(Constructor.java:513)
at org.hippoecm.frontend.plugin.impl.PluginFactory.createPlugin(PluginFactory.java:71)
at org.hippoecm.frontend.plugin.impl.PluginManager.start(PluginManager.java:84)
at org.hippoecm.frontend.plugin.impl.PluginContext.start(PluginContext.java:248)
at org.hippoecm.frontend.plugin.impl.ClusterControl.start(ClusterControl.java:112)
at org.hippoecm.frontend.Home.<init>(Home.java:111)
at org.hippoecm.frontend.Home.<init>(Home.java:64)
at org.hippoecm.frontend.InvalidLoginPage.<init>(InvalidLoginPage.java:25)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
at java.lang.reflect.Constructor.newInstance(Constructor.java:513)
at org.apache.wicket.session.DefaultPageFactory.newPage(DefaultPageFactory.java:149)
at org.apache.wicket.session.DefaultPageFactory.newPage(DefaultPageFactory.java:58)
at org.apache.wicket.request.target.component.BookmarkablePageRequestTarget.newPage(BookmarkablePageRequestTarget.java:262)
at org.apache.wicket.request.target.component.BookmarkablePageRequestTarget.getPage(BookmarkablePageRequestTarget.java:283)
at org.apache.wicket.request.target.component.BookmarkablePageRequestTarget.processEvents(BookmarkablePageRequestTarget.java:210)
at org.apache.wicket.request.AbstractRequestCycleProcessor.processEvents(AbstractRequestCycleProcessor.java:91)
at org.hippoecm.frontend.PluginRequestCycleProcessor.processEvents(PluginRequestCycleProcessor.java:31)
at org.apache.wicket.RequestCycle.processEventsAndRespond(RequestCycle.java:1175)
at org.apache.wicket.RequestCycle.step(RequestCycle.java:1252)
at org.apache.wicket.RequestCycle.steps(RequestCycle.java:1353)
at org.apache.wicket.RequestCycle.request(RequestCycle.java:493)
at org.apache.wicket.protocol.http.WicketFilter.doGet(WicketFilter.java:355)
at org.apache.wicket.protocol.http.WicketServlet.doGet(WicketServlet.java:124)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:707)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:820)
at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:511)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1166)
at org.hippoecm.frontend.plugins.login.ConcurrentLoginFilter.doFilter(ConcurrentLoginFilter.java:54)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:388)
at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216)
at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:182)
at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:765)
at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:418)
at org.mortbay.jetty.handler.ContextHandlerCollection.handle(ContextHandlerCollection.java:230)
at org.mortbay.jetty.handler.HandlerCollection.handle(HandlerCollection.java:114)
at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
at org.mortbay.jetty.Server.handle(Server.java:326)
at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:542)
at org.mortbay.jetty.HttpConnection$RequestHandler.headerComplete(HttpConnection.java:923)
at org.mortbay.jetty.HttpParser.parseNext(HttpParser.java:547)
at org.mortbay.jetty.HttpParser.parseAvailable(HttpParser.java:212)
at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:404)
at org.mortbay.io.nio.SelectChannelEndPoint.run(SelectChannelEndPoint.java:409)
at org.mortbay.thread.QueuedThreadPool$PoolThread.run(QueuedThreadPool.java:582)
Caused by: java.lang.NumberFormatException: For input string: "6 ("
at java.lang.NumberFormatException.forInputString(NumberFormatException.java:48)
at java.lang.Integer.parseInt(Integer.java:458)
at java.lang.Integer.parseInt(Integer.java:499)
at org.hippoecm.frontend.plugins.standards.behaviors.BrowserCheckPlugin$WicketBrowserInfo.parseMajorMinor(BrowserCheckPlugin.java:218)
at org.hippoecm.frontend.plugins.standards.behaviors.BrowserCheckPlugin$WicketBrowserInfo.setVersions(BrowserCheckPlugin.java:210)
at org.hippoecm.frontend.plugins.standards.behaviors.BrowserCheckPlugin$WicketBrowserInfo.<init>(BrowserCheckPlugin.java:187)
at org.hippoecm.frontend.plugins.standards.behaviors.BrowserCheckPlugin.bind(BrowserCheckPlugin.java:268)
at org.apache.wicket.Component.add(Component.java:929)
at org.hippoecm.frontend.service.render.AbstractRenderService$2.onServiceAdded(AbstractRenderService.java:207)
at org.hippoecm.frontend.service.render.AbstractRenderService$2.onServiceAdded(AbstractRenderService.java:193)
at org.hippoecm.frontend.service.ServiceTracker.addService(ServiceTracker.java:35)
at org.hippoecm.frontend.plugin.impl.PluginManager.internalRegisterService(PluginManager.java:250)
at org.hippoecm.frontend.plugin.impl.PluginManager.registerService(PluginManager.java:143)
at org.hippoecm.frontend.plugin.impl.PluginContext.registerService(PluginContext.java:171)
at org.hippoecm.frontend.plugins.standards.behaviors.BrowserCheckPlugin.<init>(BrowserCheckPlugin.java:260)
... 50 more
CMS 2010-01-28 10:59:36,609 ERROR [org.hippoecm.frontend.plugin.impl.PluginFactory] java.lang.NumberFormatException: For input string: "6 ("
Failed to instantiate plugin 'org.hippoecm.frontend.plugins.standards.behaviors.BrowserCheckPlugin' for id 'null'.