Makenshi2k: Sorry for necro posting, but this could be helpful for someone stumbling across this thread.
Installing dgVoodoo2 and setting core affinity still didn't fix the problem that the menu animation would freeze.
To fix that I needed to limit the frame rate runs in. You can possibly notice this, as you're card will start to "coil whine" as it's putting out around some insanely high fps for the game. To limit the fps you will need something like the Nvidia profile inspector. You can find the newest version easily with Google. Sorry, I cannot post links as of yet.
Start the profile inspector with admin privileges and search in the left input field "Profiles" for Blood Omen 2. Look for the entry "Frame Rate Limiter" under the heading "2 - Sync and Refresh". Limit the frame rate accordingly to 60, 120, 144 or what ever you're desired max rate is. Now the menu should behave normally.
PS:
You can start the game with a set core affinity more comfortable with a cmd script file.
1. Make a new file in notepad (not wordpad or word!)
2. Insert the following script:
@echo off
start /affinity 1 bo2.exe
3. Save it in your bo2 folder (important!) as bo2.cmd
4. Start the game
only with that executable from now on
You can make a shortcut to that cmd and give it a nice icon. Or add it to your Steam library.
You are the very best kind of person. :)
This worked for me.