Has anyone experienced imagej causing X windows to act funny and freeze.

When I start imagej several windows(gvim,firefox,?) become transparent and/or removed from the screen and subsequently X windows is unresponsive to the keyboard and mouse, albeit the mouse can move the cursor. Sometimes the freeze of X-windows is not immediate, but is before anything is accomplished in imagej. A reboot of the computer is required.

uname -a
Linux a.b 2.6.34.7-56.fc13.x86_64 #1 SMP Wed Sep 15 03:36:55 UTC 2010 x86_64 x86_64 x86_64 GNU/Linux

imagej-1.43.1.m.fc13.noarch
I have tried imagej directly from suppliers gzip, i.e. using their copy java, with the same results.

Thanks in advance,

Fred