Marcus, did you ever get your issue resolved? I have the exact same issue using Vegas Studio HD 11 and can’t seem to find a way to resolve it. I’m glad I finally found someone else that was having the problem. I run a 90 minute radio program and when I try to edit anything after 45-55 minutes (depends from time to time) the audio resets to start playing what was at the beginning of the audio file.
So, just checking to see if you had an update.