Just a FYI. I have been running Vegas 8c and Vegas 9c in Windows 7 ultimate 64 bit with an ASUS P6T deluxe v2 Motherboard w/ i7 chip. Vegas was constantly crashing hanging on renders red screens black frames etc. Could barely get anything done for the bugs. I noticed my SATA drivers were dated 2006. So I updated Sata drivers and motherboard chipset drivers and it fixed all the issues. this might save someone some headaches.
Wadro
Wadro