I've used Windows 7 since the first Beta with out a problem. Now Vista, that was a disaster. Manufacturers didn't even have compatable drivers ready by launch.
I'd have don't a clean install. It only takes about an hour. I've read of issues like your's from upgrade installs. Even Vista had those issues. Mainly what is causing the problems is various small parts of Vista being held over into the Windows 7 installation. Really, a clean install, installing all your programs, and copying over setting is the way to go.
I'm currently doing this, going from Windows 7 RC2 to Windows 7 Pro. Held off till the end as I had everything setup the way I wanted. Now I have to redo all of that. But it has to be done. Good way to force all my drivers to be up to date.
Oh, just wanted to point out that an old webcam I could not get working under Vista, worked fine with XP, mainly as there were apparently no Vista drivers for it. Windows 7 recognized the webcam when I plugged it in and got the drivers. Works great under Windows 7.
