We had a case here recently where a certain feature (inserting images using the Map menu in this case) was causing a fatal error. This was on a new install of AutoCAD Map 2006.
Neither a repair nor reinstall fixed this problem. Short of doing a manual hard uninstall as documented here:
... I thought this may have something to do with the fact that Map 2007 was once installed (but long since removed) on this machine. These applications share program file space in C:\Program Files\Common Files\Autodesk Shared.
So I renamed the \Autodesk Shared directory to something else, then ran another repair on this install - and guess what, everything works now.
Apparently, the 2007 Uninstall leaves some files around and the 2006 install (and subsequent repair/reinstall) doesn't overwrite them. Forcing the repair procedure to replace the entire \Autodesk Shared directory by deleting the old one did the trick.