brad in aus

1st: When i enter the media center in vista and go to the music library the
screen goes black and a message comes up saying its searching for the
problem. Then about a minute later it restarts media center and does this
over and over again.

2nd: The videos in WMP11 are really laggy while in Media center they're fine.

3rd: I set up some quadraphonic speakers but the back two don't work in
WMP11 even though i set them up to. I think it might have something to do
with sound effect manager which was made for XP.

Does anyone have any solutions to my problems or a sound effect manager
alternative?