Here's something weird. Normally I could just alt-tab to Winamp, and with single keypresses do things like pause or so on and then alt-tab back, but after installing Microsoft Office 2007 I can no longer do this. I have to click on the playlist, and then hit whatever keys to carry out normal operations that I could've done easily before. So what's going on?
You can switch focus between windows in Winamp by pressing Ctrl-Tab. Maybe not the perfect solution, but if you're alt-tabbing anyway it's not that hard to add those in there.