Hi, I've been having this same problem running Vista Ultimate x64 on an Intel Q9550 processor (built system myself so it's unbranded)...
I tried that compatibility mode fix, using 95 and 98/Me only result in more crashing, and using NT 4.0, works, but all icons with 'what-should-be' transparent backgrounds show up with just a black background like this -->

In addition to that, I have a friend that lives in the US and before I made my new computer, we used to talk in video conversations over MSN... However, running in NT 4.0 compatibility mode won't allow sound to be sent or received as you can't run the "Audio and video setup", this is, of course... very annoying. Please could someone find another solution to this crashing problem as the compatibility mode is not the best solution for people with webcams/microphones or people that use emoticons alot. Even if someone could simply offer me a solution to the transparency problem it would be of great help. Although, the video call problem is more critical.