There's a problem with tracks assigned to busses. If I assign track 1 to bus A and point A with the mouse pointer it reads 'preview'. I think it should read Bus A. Also, track 2 (assigned to Bus B) reads 'Master' and track 3 (assigned to Bus C) reads Bus A. Why?
I assigned track 1 to Bus A but when I check the assigment it shows Preview.
Track 3 which I assigned to Bus C in fact seems to be assigned to Bus A. And so forth.
Have you recently changed the sound card driver within the Vegas Preferences? I have had something similar in the past, but not quite what you're seeing. If I start a project using the Classic Wave driver or Windows Mapper, and then switch to the ASIO driver, my output assignments on my buses will get reversed using my dual Gina card setup.