Yes, according to Sony Creative Software tech support, Vegas Pro 10 does not allow network rendering. IMHO, this was an expensive addition to the software, and they probably got more calls than they wanted. Also, the average editor isn’t exactly the nerdy network guru, too (me included).
I’m giving up on 10 for now, since I want network rendering speed. I live in a 64bit world, but i need a little more horsepower.