Your computer sucks, get a new one. It runs fine on mine and even great after the patch, even though I had to restart the entire adventure from scratch (which was kind of annoying seeing as I was level 75+ with only a few broken steps of the main quest to go..). I haven't had a Guru crash or Stack overflow crash since installing 1.6. By the way, try running an unpatched version of Gothic 3 first and then install the 1.6 patch, if you think it doesn't do anything! I'm getting 10-15% better framerates, a lot less stuttering, improved loading/saving times and a BILLION little odd bugs removed.