I have had no problems for 6 months. Until last week. When I place a .mts file on the timeline it will hit a snag (for a second) then the video goes into slow motion and the audio stays normal- they end up way out of sync. The crazy thing is this will happen at different points in the file. Once I encounter a snag the problem gets worse, sometimes causing the entire file to have the problem where the video starts off in slow motion and the audio is fine. This is happening on both of my systems in the same way.

If I render the file the same thing happens. Again this will be worse if I do anything to the file on the timeline. Just regular editing worsens the problem.

The intermittent and progressive nature of the problem have me baffled.

I have been trouble shooting for the last 4 days. Please Help?