From what you posted, this section concerns me:
crystalspace.graphics3d.shader.fixed:
Multitexture units: moderate 4
psEngine destroyed.
X Error of failed request: BadWindow (invalid Window parameter)
Major opcode of failed request: 4 (X_DestroyWindow)
Resource id in failed request: 0x3c00003
Serial number of failed request: 172
Current serial number in output stream: 174
That X Error more than likely is the cause, or even the result of the problem, I just can't tell. When I get X Errors, I just reinstall the OS and or game. I am running Opensuse 10.2 and have never had any problems, however I had many on Ubuntu. If your not into reinstalling th OS, I would first check that drivers are working and up to date. Next, see if you have a decent graphic card capable of running it well. Next, check your Xorg version, make sure it is up to date as well. If all that fails, I would reinstall the game itself. And of course, the last option is that OS reinstall, but that may not produce results. Good luck, hope you can fix it.