I need to insert more time into the beginning of a scene so everything gets pushed back in the timeline. I had success the first and second  try but I need more frames inserted and now it throws the face motions out of timing with the voice. I hit undo (timing is back) and tried again and timing is off. I tired restarting the program and the same results. Is there a limit to how many frames that can be inserted? I think I have inserted 40 or 60 so far.