Internal link in Xinha field does not get correctly url encoded

The url encoding of internal links with in a Xinha field get url encoded in the wrong way (not UTF-8).
I've attached a png file and if you:

• upload it in the assets folder
• open a document with a xinha field
• add a bit of text
• make a link out of the text to the uploaded image
• try to modify the link

the following exception will occur.

30.01.2009 14:07:07 ERROR [org.apache.wicket.RequestCycle.logRuntimeException():1437] URLDecoder: Illegal hex characters in escape (%) pattern - For input string: "u0"
java.lang.IllegalArgumentException: URLDecoder: Illegal hex characters in escape (%) pattern - For input string: "u0"
at org.apache.wicket.protocol.http.WicketURLDecoder.decode(WicketURLDecoder.java:160)
at org.hippoecm.frontend.plugins.xinha.XinhaUtil.decode(XinhaUtil.java:35)
at org.hippoecm.frontend.plugins.xinha.services.links.InternalXinhaLink.createInitialModel(InternalXinhaLink.java:48)
at org.hippoecm.frontend.plugins.xinha.dialog.DocumentLink.<init>(DocumentLink.java:40)
at org.hippoecm.frontend.plugins.xinha.services.links.InternalXinhaLink.<init>(InternalXinhaLink.java:38)
at org.hippoecm.frontend.plugins.xinha.services.links.XinhaLinkService$InternalLink.<init>(XinhaLinkService.java:136)
at org.hippoecm.frontend.plugins.xinha.services.links.XinhaLinkService.create(XinhaLinkService.java:48)
at org.hippoecm.frontend.plugins.xinha.dialog.links.InternalLinkBehavior.respond(InternalLinkBehavior.java:43)

This does work for images though, so it must go wrong with the encoding of an internallink.