Unfortunately, this is a recurring problem for most players. The mods you have installed have nothing to do with it. I'm not sure anyone has completely debunked the cause, but it's most likely a problem with how the engine renders the graphics.
There are a few urban myths you can try to reduce the freezing, but I'm not sure any of them truly work:
- Right click on the DF2.exe shortcut, choose properties, click the compatibility tab, and choose "Run in compatibility mode for: Windows XP" (you can also choose Windows 98).
- Download this utility, then update the game and apply the Vista Fix (you'll need to register on their site before viewing the thread):
http://www.thegoodoldays.com/forumcg...8717398/s-new/
- Try sticking with the 800x600 or 640x480 (<-- preferred) resolutions. I've found that higher resolutions cause freezing MUCH more frequently.
Even after these fixes, you're probably guaranteed a freeze or three if you play 2+ hours. It's a fact of life we DF2'ers have been forced to accept.
P.S.: Alternatively, you could try buying a Windows 98 machine and running it on that. I don't remember freezing any in those days.
