Message tone played multiple times on receiving message/notification on iOS 5
Ok, I had the exact same issue after updating to IOS 5, SMS tones sounded like a stuck record and very garbled. Solution is back-up your iphone then do a complete restore and at the end set up as a new iphone NOT backup from previous. The back-up can cause glitches when 1st updating from 4.3.5 to 5. Then unplug and plug back in and right click your iphone and do a "restore from back-up" after the setup as new iphone. Hope that helps for you as it did for me.