I had this occasionally on previous versions of Vegas where when you opened a project a peak would rebuild for some reason and you had to wait a few minutes, but it seems like V8 is doing this quite a lot... I never understood thais because if the sfk is in the same directory as the video file why does the program rebuild it, wasting a crapload of time....?
I noticed DVDa 4.5 doing the same thing. DVDA doesn't handle m2ts any better than 4 and peak building is slow as moleasses compared to V4...