It has definitely NOTHING to do with the firewall.
Firewall problems cannot make your graphical session (Xorg) crash.
Most likely that’s a graphics driver issue.
Somebody had the same issue recently on the opensuse mailinglist.
For him re-installing the nvidia driver fixed it. (there was an xorg-x11-server update, if you installed the nvidia driver “the hard way” the update overwrites a part of the driver, because the driver overwrites system libraries on installation in the first place) http://lists.opensuse.org/opensuse/2014-04/msg00824.html
So, what graphics card/driver are you using?
Install “Mesa-demo-x” if it is not installed already, and post the output of:
The command you posted seem not to be working for me:
jakob@linux-hkem:~> glxinfo | grep render > out.txt
X Error of failed request: BadWindow (invalid Window parameter)
Major opcode of failed request: 154 (NV-GLX)
Minor opcode of failed request: 4 ()
Resource id in failed request: 0x4e00003
Serial number of failed request: 33
Current serial number in output stream: 33
If you install the driver by downloading and installing the .run file from NVidia’s homepage, you have to reinstall it whenever there is an update to xorg-x11-server, Mesa-libGL1, or the kernel. (as I said, it replaces two system libraries with each own version, namely libglx and libGL)
That’s why I always recommend (and prefer myself) to use the ready-made RPMs from the nvidia repo.
Those install the driver in a way that it will still work after such an update.
But the RPMs won’t work of course if you use a different kernel than the one included in openSUSE…