Logic Pro 7 & earlier Audio file problem


OK. I just opened up some older files tonight and the vocal audio tracks are dipping volume here and there (no real pattern). My computer has gone down (Mirrored door G4) in the last 6 months twice; first a power supply, secondly a month ago, the logic board. Did I possibly damage the audio files somehow in all this chaos? I'm getting ready to buy a quad core i7 iMac. Running 7.1.1 with 10.4.11.