I'm running it on two Win7 64-bit machines and one XP-machine.
On one of the W7-machines it one day started to misbehave badly, crashing after a couple of minutes and so on. I saved up three or four different screenshots (same screenshot but different error code or whatever each time) in order to have something to show but then it just stopped doing it and has been running fine since - for a couple of weeks, not used very much though but never the less.

On the other W7 machine and on the XP machine I haven't had any problems.

If/when you find something, please post your findings!
/Henrik.