Hi John,

I hope this tip will resolve your issue pertaining to Q2-041106: MDT 2004 Conversion to Inventor 11, I am not so sure but give a try as shown below:
Open Windows Explorer and navigate to C:\Program Files\MDT 2004, which will be the default location and will vary if the user has installed in different folder.
Later double click the file name Mechanical Desktop 2004 Basic. After running Mechanical Desktop using basic profile, you will be able to translate MDT files into Inventor.

I hope this will help. If not I am really sorry for bothering you.

Take care,
Alecia