Selection plugins: entering value in StaticDropdown selectable.options property in document type editor causes exception

The Selection Plugins' StaticDropdown plugin has a configuration property 'selectable.options' which accepts a comma separated list of values to populate the dropdown. This works when the property is added through the CMS Console or XML initialization, but not in the CMS document type editor.

Reproduction path:

In the document type editor, create new document type.
Add a StaticDropdown field.
In the properties, enter a value in 'selectable.options'
Nothing happens in the CMS GUI but an exception stacktrace is logged:

[INFO] [talledLocalContainer] 13.02.2012 10:04:15 ERROR [org.apache.wicket.RequestCycle.logRuntimeException():1531] Null object returned for expression: selectable.options for setting value: on:
[INFO] [talledLocalContainer] org.apache.wicket.WicketRuntimeException: Null object returned for expression: selectable.options for setting value: on:
[INFO] [talledLocalContainer] at org.apache.wicket.util.lang.PropertyResolver.setValue(PropertyResolver.java:138)
[INFO] [talledLocalContainer] at org.apache.wicket.model.AbstractPropertyModel.setObject(AbstractPropertyModel.java:182)
[INFO] [talledLocalContainer] at org.apache.wicket.Component.setDefaultModelObject(Component.java:3173)
[INFO] [talledLocalContainer] at org.apache.wicket.markup.html.form.FormComponent.updateModel(FormComponent.java:1183)
[INFO] [talledLocalContainer] at org.apache.wicket.ajax.form.AjaxFormComponentUpdatingBehavior.onEvent(AjaxFormComponentUpdatingBehavior.java:155)
[INFO] [talledLocalContainer] at org.apache.wicket.ajax.AjaxEventBehavior.respond(AjaxEventBehavior.java:177)
[INFO] [talledLocalContainer] at org.apache.wicket.ajax.AbstractDefaultAjaxBehavior.onRequest(AbstractDefaultAjaxBehavior.java:302)
[INFO] [talledLocalContainer] at org.apache.wicket.request.target.component.listener.BehaviorRequestTarget.processEvents(BehaviorRequestTarget.java:157)
[INFO] [talledLocalContainer] at org.apache.wicket.request.AbstractRequestCycleProcessor.processEvents(AbstractRequestCycleProcessor.java:92)
[INFO] [talledLocalContainer] at org.hippoecm.frontend.PluginRequestCycleProcessor.processEvents(PluginRequestCycleProcessor.java:95)
[INFO] [talledLocalContainer] at org.apache.wicket.RequestCycle.processEventsAndRespond(RequestCycle.java:1252)
[INFO] [talledLocalContainer] at org.apache.wicket.RequestCycle.step(RequestCycle.java:1331)
[INFO] [talledLocalContainer] at org.apache.wicket.RequestCycle.steps(RequestCycle.java:1438)
[INFO] [talledLocalContainer] at org.apache.wicket.RequestCycle.request(RequestCycle.java:546)
[INFO] [talledLocalContainer] at org.apache.wicket.protocol.http.WicketFilter.doGet(WicketFilter.java:486)
[INFO] [talledLocalContainer] at org.apache.wicket.protocol.http.WicketFilter.doFilter(WicketFilter.java:319)
[INFO] [talledLocalContainer] at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
[INFO] [talledLocalContainer] at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
[INFO] [talledLocalContainer] at org.hippoecm.frontend.ResourceRewriteFilter.doFilter(ResourceRewriteFilter.java:129)
[INFO] [talledLocalContainer] at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
[INFO] [talledLocalContainer] at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
[INFO] [talledLocalContainer] at org.hippoecm.frontend.plugins.login.ConcurrentLoginFilter.doFilter(ConcurrentLoginFilter.java:54)
[INFO] [talledLocalContainer] at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
[INFO] [talledLocalContainer] at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
[INFO] [talledLocalContainer] at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
[INFO] [talledLocalContainer] at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
[INFO] [talledLocalContainer] at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
[INFO] [talledLocalContainer] at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
[INFO] [talledLocalContainer] at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:589)
[INFO] [talledLocalContainer] at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
[INFO] [talledLocalContainer] at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:291)
[INFO] [talledLocalContainer] at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:859)
[INFO] [talledLocalContainer] at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:602)
[INFO] [talledLocalContainer] at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489)
[INFO] [talledLocalContainer] at java.lang.Thread.run(Thread.java:662)