very slow sound playback for unclear reasons

Ever since i installed hardy beta i have been having problems with my sound. It all of a sudden slows down to a funny sounding but very unusable tempo. Sometimes this problem starts at the login window, making the login sound (the first, short one) echo everything from a little bit to a lot. Other times login is fine but somewhere later in the session the sound slows down. I've noticed that my soundcard or something in that direction has problems with being used by different programs, if i open a movie in totem, close totem, and open the same movie in vlc the sound is not working.
I read some very old posts about slow sound where people chanced the sample rate of their soundcard. I have no idea how to do that but i am very willing to try that and every other solution provided!

thanks in advance