while running firefox with quicksynergy the system locks up

[treetop]

Binary package hint: firefox-3.5

release: 9.10, karmic koala

Running: Firefox v. 3.5.8 canonical 1.0
Running: QuickSynergy

At times Firefox locks up but I am able to move the mouse pointer around on the screen. The use of the keyboard is inhibited also. A few times I was able to click on the 'x' to close firefox but most times I have to power down. When firefox reloads I get the 'well this is imbarasing ...' tab. Closing this tab or continuing this tab will allow me to continue using firefox but soon thereafter the system locks up again requiring another cold boot.

ProblemType: Bug
Architecture: i386
CheckboxSubmission: 669f04841ab71372154ea4a0d40a6ff6
CheckboxSystem: 46f09c1998a067682e63e8785346abf0
Date: Mon Feb 22 21:08:24 2010
DistroRelease: Ubuntu 9.10
InstallationMedia: Ubuntu 9.10 "Karmic Koala" - Release i386 (20091028.5)
Package: firefox-3.5 3.5.8+build1+nobinonly-0ubuntu0.9.10.1
ProcEnviron:
 LANG=en_US.UTF-8
 SHELL=/bin/bash
ProcVersionSignature: Ubuntu 2.6.31-19.56-generic
SourcePackage: firefox-3.5
Uname: Linux 2.6.31-19-generic i686
XsessionErrors:
 (gnome-settings-daemon:1440): GLib-CRITICAL **: g_propagate_error: assertion `src != NULL' failed
 (gnome-settings-daemon:1440): GLib-CRITICAL **: g_propagate_error: assertion `src != NULL' failed
 (nautilus:1554): Eel-CRITICAL **: eel_preferences_get_boolean: assertion `preferences_is_initialized ()' failed
 (polkit-gnome-authentication-agent-1:1561): GLib-CRITICAL **: g_once_init_leave: assertion `initialization_value != 0' failed
 (firefox:1729): GLib-WARNING **: g_set_prgname() called multiple times