I am having the same issues Using Sony Vegas Pro 11 & 12 with the Panasonic GH3… I have been shooting AVCHD files and it seems to be OK when I put AVCHD or .MTS files on the timeline…
Today when I put the GH3 files… 24 P .MOV files on the time line it extends the video file way beyond the audio…
This is most frustrating… Have you contacted Sony Creative software support regarding this issue?
Kindest and sincerest warm regards,
Lisa J. Kassner