Apple Logic Pro /LogicExpress Discussion

Hey, I had a weird thing show up today. My EXS24 instrument are going  
out of tune.  I have checked the list view and taken everything but  
the notes, and it affects different instruments or goes out of tune  
at different times. I recorded one sample where the mandolin goes  
sharp about 1/3 of the way through.

http://www.brokenpick.net/PitchProblems.mp3

Does anyone have any idea why this would happen?  And don't say it's  
the EXS problem that comes with cracked version.  It's not a crack.

Thanks

Gregory