When I play RCT, there's an annoying 'buzzing' noise all the time in the game. It's most noticeable if you make the game quiet (look far away from your park, etc). Has anyone else had this problem - and if so, have you managed to find a way to stop it?

This sound only appears in RCT for me (it's certainly not in the majority of other games or audio playback)

I'm running Vista, and have an Xonar sound card (they seem like the most likely things that matter, if anyone thinks other specs might matter, just ask)

Any feedback much appreciated!