While I playing campaign in Nexuiz 2.3, I was shot by a rocket launcher, and the game froze. Then the not responding window showed up. When it finally closed down, I restarted the game, and in the screen shot for the level in campaign, there was a checkered grid,gray an white. So I closed down Nexuiz, and looked at the files. All of them were marked as system or hidden files, and had strange ASCII characters in the name. (like the boxes, and others, like the square root symbol.)

I am running Windows 2000
NVIDIA Geforce 5200
612 Mb RAM
2 Ghz Processor

(^^^If I'm missing something vital let me know)

However, these files are on an external USB hard drive, (60 Gb) Which could be the fault, but Nexuiz 2.1 works perfectly fine on my 1 Gb SanDisk Flash Drive.

Looks like file system corruption. Your USB stick may be broken now. Try reformatting and using it again.

false alarm. figured out what the problem was. for whatever reason, when I have the external USB hard drive plugged into one of the ports, I can't access some folders randomly, but if I try again, I still can access them, so as the game was attempting to access some file, the I/O error screwed everything up. The hard drive still works perfectly fine on the other port though.