I think your problem was renaming the files. I couldn't find this documented anywhere, but the way I've gotten this to work on a CG6 was to keep the Sanyo naming conventions: e.g. SANY0123.MP4 for video or SUND1234.M4A for audio.
This is sort of an oddball question. I shot a boatload of videos with the CG 65 and downloaded them to an external hard drive, and from there to a PC. There was NO editing whatsoever on the PC; but I did rename the files.