Render As button greyed out

Using Vegas 11 build 683 64 bit windows 7. I finished a project and clicked on "render As" b utton. When the format selection window pops up, it is by defult on Sony .mxf file format and the render button is active. I want to save to Main Concept MPED-2 but when I select that format or any other format that is not in the Sony sub list of formats, the Render button greys out and I can't render.

Funny thing is I've used Vegas for years since Ver. 8 and never had an issue. I bought the retail box version of 11 and installed first on my Laptop and was able to render with no problem. Installed Vegas on a new PC, registered it with serial # the other day and then closed it and computer. Today when I started Vegas to actually do some work on my new desktop, the registration window poped up again. I filled in the serial # again and registered and then the program opened. After having the rendering issue, I turned on my laptop to see iof maybe a setting needed to be changed. I figured I'd compare the version on the Laptop since it worked. Note, the laptop was not connected to the internet, so no conflict with running 2 instances of the program at the same time. Well to my surprise, now the Vegas on my laptop that worked fine a day or 2 agao, now has the same issue with the render button.

Anyone have any idea odf what's going on?