The captures ARE the ones at fault!
And one of the many variables i mentioned, this is one of them, where for one user it works fine and
for another it does not work properly at all or have certain unexplained artifacts in final render.
That is why it is not a 100% reliable source for re-editing.
A solid solution for your issue is unknown and a re-installation of Vegas is not going to help.
By the way, what version of Vegas are you using and briefly what are your system specs?
Steve Rhoden (Cow Leader)
Film Maker & VFX Artist.
Owner of Filmex Creative Media.
Samples of my Work and Company can be seen here:
https://www.facebook.com/FilmexCreativeMedia