I've had a number of strange render crashes using GPU acceleration in Vegas 11 / b425
After swapping the Asus GTX 460 card to a Gigabye GTX 460 all problems are gone
GIGABYTE - Graphics Card - NVIDIA - PCI Express Solution - GeForce 400 Series - GV-N460OC-1GI (http://www.gigabyte.com/products/product-page.aspx?pid=3530#ov)


/magnus