Vegas error, again!

[Tackleberry]

My problems with Vegas never seem to end... Now I can't render with the wmv-codec. When I select it the desription says "No existing templates support this media.". If I try to select a template it says "The custom template you selected is not valid with the current project settings. It has been filtered out of the template list."

I get that message with all templates and project settings, so it's really weird. I'm working with some projects atm, so I really need to solve this. Please give suggestions on what to do.

Thanks in advance.