FULL PRODUCT VERSION :
java version "1.6.0_17"
Java(TM) SE Runtime Environment (build 1.6.0_17-b04)
Java HotSpot(TM) Client VM (build 14.3-b01, mixed mode, sharing)

ADDITIONAL OS VERSION INFORMATION :
Linux 2.6.31-17-generic #54-Ubuntu SMP Thu Dec 10 16:20:31 UTC 2009 i686 GNU/Linux

(32 bit)

A DESCRIPTION OF THE PROBLEM :
See Bug 6714678, which is still broken.

Since I cannot reopen it, I'm filing this bug instead.

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Set a breakpoint somewhere in a method triggered by an event/action handler (e.g. a button press).

Once the application hits the breakpoint, the X window system freezes. Workaround as in issue 6714678.

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
No freeze.
ACTUAL -
Freeze. The only way to unfreeze is to switch to a console and kill the debugged java process from there.

REPRODUCIBILITY :
This bug can be reproduced always.