I had problems with Vegas pro 8 crashing with a six minute video, but the reason is My source files we 14,000 six meg targa files to be rendered at 1080 60p and 720 60p. I had to do it in two parts, render each half as uncompressed, then render those two files to my finals. I don’t think the amount of tracks is the issue as I’ve had projects with almost 30 tracks and had no problems.
Hope this helps, Danny Hays, Universal Studios FL