Having icefaces-ee-compat.jar leads to multiple problems which all go away if the jar is removed from the classpath. This issue seems to be related to IPCK-290

Steps to reproduce the problems:
Download Liferay 5.2.3 + Tomcat 6 Bundle
Download ICEfaces EE 2.0.0.GA Bundle
Deploy component-showcase-portlet.war to Liferay
Start Liferay (And get a coffee until it has started up :-D )
Login as Bruno, the Admin
Add the ICEfaces 2 "Buttons and Links" Portlet to the page
Enter some text into the "Input Text" field
Click the "Command Button" Submit Button
See that the entered text is updated in the "Server-side Backing Bean Values" panel
Change the text in the "Input Text" field
Again, click the same Submit button
Again, see the the entered text is update in the other panel

Now stop Liferay
Put icefaces-ee-ext.jar into the liferay-portal-5.2.3\tomcat-6.0.18\webapps\component-showcase-portlet\WEB-INF\lib folder
Start Liferay again (you've still got some coffee, no need to get another one)
Do the same steps with entering a text twice again
Notice these bugs:
- With Firefox 3.6.17: Only the first click on the command button seems to have an effect in the UI. All further clicks don't show a reaction at all
- With IE 8: Subsequent clicks on the button work, but after the first click the screen is messed up (See screenshot)

Firefox 3.6.17 -> Nur der erste Click funktioniert, alle weiteren nicht mehr
IE 8 -> Clicks work, but after first Click Styling is messed up