I have a Panasonic Lumix TZ5 which uses 8 bit PCM audio in its MOV file output. When I use version 2.83 of MP4Cam2AVI to convert the file using the "no recompression" option for audio, the program appears to drop the last frame of the audio data. For example, if I shoot at 30 FPS, then the audio data is 0.033 seconds shorter than the video data. If I shoot at 15 FPS, then the audio data is 0.067 seconds shorter than the video.
An easy work around is to use "PCM (uncompressed)" for the audio output. This converts the samples to 16 bits and doesn't drop the last frame.