One of the first things I did when I built my QX6700 based system (XP and Vegas 7.0d) was try to run the VASST HD dual core render test…and it crashes at between 21 and 32 seconds (a motion blur bit). Somebody on another forum who had the same problem suggested reducing the number of render threads (Preferences) – and if you reduce it to 2 it rendered fine but of course completely defeats the object of having a quad core system. I’ve logged it with Sony support.
I had a similar problem to this – and again it was particularly noticeable on hand movements. But – I had the picture reduced slightly within a border and I think it was that resize that caused the problem. Selecting “Reduce Interlace flicker” solved the problem for me.