I have this issue with pp cs5 - 5.0.3
Importing a 720p .MOV clip from a compact camera "canon powershoot a3300 is", the video preview, editing and quality is ok but the first 3 second of audio is looped along the clip duration.
All the player, quicktime 7.6.9, Vlc, play the clip and the sound is good.
Gspot say: codec avc1 - H.264 audio raw 8-bit unsigned 12000 hz
Vlc say: H264 - MPEG-4 AVC (part 10) (avc1) audio PCM U8 (u8) mono 12000 hz
Qt say: H264 1280x720 - 8 bit - mono - 12.000 khz
With other clip from my sony xdcam ex1 or other format... premiere cs5 go fine
Another system with premiere cs4, the import and the editing is ok.