I was also getting error “0x80010105” when trying to render. I am running Windows 7 (Build 7100)x64 bit. I tried basic trouble shooting steps. I right clicked on the Vegas executable then selected properties. Went to the compatability tab and selected to run in compatability mode “Windows Vista (non service pack)” (Again I chose Vista because I have Windows 7). I also checked “Run as administrator” and poof! it worked the next time I tried to render. FYI I think even if you have Windows Vista SP1 you can try compatability mode and set it to non-service pack. If it still fails then you can always upgrade to WIndows 7 RC and set to compatability mode like I did. I have a feeling that it has to do with Windows Vista SP1.
Windows 7 is the best!