I found this online:
Since then, there has been 5 (!!!) official patches that solved various problems. Patch to version 1.2, then to 1.3, to 2.0, next to 2.2 and finally 3.0. Also, 2 official add-ons came out, which contained a little bit more than just patches to versions 2.0 and 3.0 respectively: new creatures and artifacts.
Do you have the two official add-ons installed? If not, I'm wondering if that would make a difference.