I had this issue with a later update to MM3. The install seemed to find an old MM2.5 install on another drive other than C: and proceeded to extract info for the current install from this.
Once I realised what was happenning I uninstalled 2.5 and re-installed MM3 and the problem had gone.
For some reason the install process seems to see MM2x as default installed programme when it's installed on the system and overides the currrent install.

Perhaps if you isolate your MM2x install and re-install MM4 it will go as expected?

i only got the mm 3 database to import on mm 4

at one point I was asked to import my MM 2.5? settings, I chose no then, and got the new default layout.

How do I force a re-import of mm3 settings, specifically the UI elements, screen size, columns, sorting, etc.