Firefox crash because of invalid pixmap parameters

Binary package hint: firefox-3.0

Kubuntu intrepid, kde 4.2.2, FF 3.0.8

After trying to install firebug addon, just when the confirmation window pops up, firefox crashes with this dump...

hofer@rudix:~/doc$ firefox --sync
QPixmap: Invalid pixmap parameters
The program 'firefox' received an X Window System error.
This probably reflects a bug in the program.
The error was 'BadAlloc (insufficient resources for operation)'.
  (Details: serial 114349 error_code 11 request_code 53 minor_code 0)
  (Note to programmers: normally, X errors are reported asynchronously;
   that is, you will receive the error a while after causing it.
   To debug your program, run it with the --sync command line
   option to change this behavior. You can then get a meaningful
   backtrace from your debugger if you break on the gdk_x_error() function.)
Locking assertion failure. Backtrace:
#0 /usr/lib/libxcb-xlib.so.0 [0xb651d7c7]
#1 /usr/lib/libxcb-xlib.so.0(xcb_xlib_lock+0x2e) [0xb651d96e]
#2 /usr/lib/libX11.so.6 [0xb6b83619]
#3 /usr/lib/libXrender.so.1(XRenderFreePicture+0x41) [0xb6c34f41]
#4 /usr/lib/libQtGui.so.4 [0xb4b176bf]
#5 /usr/lib/libQtGui.so.4 [0xb4b1817d]
#6 /usr/lib/libQtGui.so.4(_ZN7QPixmap5derefEv+0x5d) [0xb4b0c9ad]
#7 /usr/lib/libQtGui.so.4(_ZN7QPixmapD2Ev+0x30) [0xb4b0ce10]
#8 /usr/lib/libQtGui.so.4 [0xb4b120ba]
#9 /usr/lib/libQtGui.so.4 [0xb4b1272f]
#10 /usr/lib/libQtGui.so.4 [0xb4b11d5a]
#11 /lib/tls/i686/cmov/libc.so.6(exit+0x89) [0xb7e2cd89]
#12 /usr/lib/libgdk-x11-2.0.so.0 [0xb673b707]
#13 /usr/lib/libbonoboui-2.so.0 [0xb6296d15]
#14 /usr/lib/libX11.so.6(_XError+0x109) [0xb6b7bef9]
#15 /usr/lib/libX11.so.6 [0xb6b83fe8]
#16 /usr/lib/libX11.so.6(_XReply+0x15a) [0xb6b8439a]
#17 /usr/lib/libX11.so.6(XSync+0x67) [0xb6b77667]
#18 /usr/lib/libX11.so.6 [0xb6b77805]
#19 /usr/lib/libX11.so.6 [0xb6b847c2]
Killed
hofer@rudix:~/doc$

ProblemType: Bug
Architecture: i386
DistroRelease: Ubuntu 8.10
NonfreeKernelModules: nvidia
Package: firefox-3.0 3.0.8+nobinonly-0ubuntu0.8.10.2
ProcEnviron:
 SHELL=/bin/bash
 PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games
 LANG=en_US.UTF-8
SourcePackage: firefox-3.0
Uname: Linux 2.6.27-14-generic i686