I am having trouble with Vegas 9 64 bit, Win7 64 Bit opening project files saved in Vegas 9 32 Bit, WinXP 32 Bit. Tried to open the files on another system and no luck - states something about permission (Totally incorrrect error message)
Strange - I have used Vegas 9.0c 32 bit on Win7 64 bit until yesterday.
This morning I installed 9.0d 64 bit and it opens all the old vegs - also the ones from 8.0c that 9.0a,b,c 32 bit did not like.
Dunno if it helped, but I deleted all *.sf* files in all media libraries first...
Messages about permission normally come from Windows.