Hi,
As I also use Pro-E I hadn't been on MDT for some time. I installed V6 and lost the file-opening menu during a failed IGES import task. Setting FILEDIA and CMDDIA to '1' fixed it!
Thank God this post was up. This problem was driving me nuts! I had a failed IGES import into my MTD6, deleted it and imported an ACIS version instead. After that I lost all of my pop-ups, save as, holes, extrude etc. Setting FILEDIA and CMDDIA back to 1 got me back on track. Thanks guys!!!