I'm using Samplitude ProX 4 Suite. I've never had a wav file ripped from a CD corrupt when the ends are trimmed or when the tempo is changed. A fair number of mp3s corrupt in different ways when I start to manipulate them. When I trim the length, I get extra beats. When I change the tempo, the sound quality corrupts big time. Is there a way to avoid this happening? I don't believe it's a software problem. I believe it's a problem I don't understand with some mp3 files. But is there a way within software to ask the file to respond correctly? Import in some different way, convert to another file type? I'm partly just curious about why this would happen to some mp3s and not others. Does it relate to the way it was originally produced?