I am having the exact same audio issues with footage I shot. I spent months merging my dual-system audio to the camera video. In some cases, we had a high-quality camera audio track, which I kept.
Now all the camera audio is out of sync. I have been reading that Premiere Pro as issues with tracking audio. It is unbelievable. This software has over a dozen versions behind it; there is no way it should lose audio tracking. And I have also read that this isn't even fixed in CS6, which I upgraded to but can't use for other reasons (see other post).
For the record, I am editing AVCHD out of an FS100
6 core Intel
24 GB RAM
3 TB RAID
Win7 Ultimate SP1
Production Premium CS5.5 & 6 (audio issues with both)
I had the same problem with some footage I shot on Saturday. The footage was shot with the Panasonic AF100, with audio in the LPCM format.
After I ingested the footage with Prelude, some of the later clips were badly garbled. At random intervals, the audio would "skip ahead" and lose sync. The audio would finish early and the there would be silence for the second half of the clip. All of the early clips were fine, the later ones were garbled.
I was able to use another take where the audio was fine, but I was certainlty worried. Was my camera malfunctioning? Was it an SD card error? Was it a Premiere bug?
I finally got a chance to revisit this today. The data was still on the card, so I put it back to the camera and played it back. The audio was fine. So it was definitely Premiere.
In Premiere, I deleted the Media Cache (Edit->Preferences->Media) and while I was at it I selected "Save Media Cache Files Next To Originals" so in the future it would be easier to figure out which cache files went with which clips.
After Premiere reconformed the audio, the problem diasppeared.
I've been using this camera with Premiere for the last year, and have been using Premiere for many years and have never seen this issue in the past. So I assume it's a new quirk, something we'll have to keep alert to in CS6.
Thanks for the advice re: Media Cache Files. I had another work-around for my current project, and wasn't game to try anything new in the middle of it. I will use this approach from now on though.
Had the same problem and as Save Media Cache was already clicked by me, I deleted the cache file. Adobe regenerated all right.
Seeing the dates of your posts, I'm a little bit surprised that this issue hasn't been fixed by Adobe by now