I've got an issue with the audio sounding like it has an echo filter when playing Unreal Tournament 2004 on Windows 7 x64. This issue goes away if I (after starting ut2k4) go to playback devices and configure the speakers to run some other setting (stereo, 5.1, 7.1) than currently set, and then set them back again. This will only work once though, and next time I start ut2k4, the issue is back and I have to do this again. As you might imagine, this is kind of annoying.
Any ideas? I'm using SoundBlaster Audigy.