Created attachment 4983
sample java app that demonstrates the problem
Please run the attached sample:
java -jar xfwm4vsjava.jar
1) Click "Open non modal window" button
2) A new window should open. In this window none of the buttons are clickable.
The window in the back seems to receive all the clicks, for example if the dialog si overlapping the main window, any click on the dialog it's received by the main window.
Weird things seem to happen with modal windows too, but I wasn't able to replicate it reliably. But if you play with it long enough you will see it happen.
These issues seem to be specific to Swing based applications. Eclipse (SWT base) seems to work fine.
Tested with OpenJDK 1.7.0_15 64bit and Oralc JDK 1.7.0_17 64-bit.
Java 1.6.x seems to work fine.
I've got another Linux system with Mate DE (Gnome based?) and it's also working fine there.
Let me know if there's anyhting else I can do to help with this.
This may be a Java bug. I have opened a similar bug report here: http://icedtea.classpath.org/bugzilla/show_bug.cgi?id=1532 Could you post the source of the sample application there? It could help in fixing the bug.
I can't reproduce this bug with OpenJDK 1.7.0_99 nor 1.8.0_77 on Arch Linux.