OK, if you wanted, you could actually delete the .mnr and mnc files, they will get recreated everytime you start AutoCAD anyhow.
That might not be a bad idea, at least once.
OK, so let's just talk .mns files
You have a custom file (.mns) in each directory?
Do you have a support apth to each directory? This is a must.
If the problem continues, I would try renaming one of the menus (open the file) menugroup = newname
May be name of 2002 nd one 2005
Also, keep in mind that 2005 was very buggy, we just unloaded it altogether, we are getting 2006.
Mark