Gah. They got back to me and requested a dxdiag.txt. I sent that to them, along with a more detailed description of my symptoms and they responded saying to upgrade my sound card drivers and turn of all my startup programs, and disable anti-virus realtime scanning.
My sound card drivers are already on the newest version, according to Asus (onboard Realtek sound). I suppose it is possible that there are newer drivers for this Realtek chip someplace else, but I have no idea if they'd truly be compatible with my system.
As far as turning off startup programs, that reminds me of all the games back in the early and mid-90's that would ask you to make sure there aren't any TSRs running. This is 2009! I shouldn't have to do this! All of my other games work fine (except Gears of War, but that's another story)!
I'll do what they ask just to say I did, but I am certain it won't correct the problem.