~~Welcome Eva~~ to the board!!
Strange problem you got there hmmm have you installed the latest patch? trie that to se if it help`s and make sure your hardware acceleration is ON for the video card!!
If this not help the i sugest you report to Sir-Tech and ask them abouth the problem! her is the link to them!
http://www.wizardry8.com/index2.html
Hope you get some help there!