I replaced the mainmenu.py with the one in the post you provided, but the main menu is still "locked".

No change at all, but thanks again for trying! I'm going to make a fresh copy and do some trial and error, maybe a file is misplaced.
UPDATE: Well, the only thing I could do is replace the mainmenu.py that came with the UMM1.0 with a stock file from a fresh copy. Doing this fixed the "locked" menu and I have mutators, but no configuration option. A little progress made at least
UPDATE2: I have tried to install UMM1.0 on 4 different fresh copies of BC. All with the same result, a "locked"menu". They all have 1.1 patch and foundation. I can't see why this is giving me so much trouble
UPDATE3: I tried making a fresh copy, applied the 1.1 patch and downloaded BCUT. From there, I let BCUT install the foundation that came with it. I then used the mod installer and directed BCUT to the UMM1.0 zip file from BC files. I hit the install button. BCUT said it installed successfully. I then launched the game. When I reached the Main Menu, It was the same problem. A "locked" main menu. I can click on the buttons that say "configure" "quick battle" etc.., but the screen stays on the main menu. Again, I had to use task manager as the "quit" button will not work either. I installed the mod directly from the zip file just as BCUT instructed! I even have the root folder on my desktop just to be sure it isn't a vista problem. I'm totally clueless as to how to solve this issue. Oh, and before anyone asks, YES I have a 100% legal copy of the game that I bought in 2002.
PS: I have put aside a COMPLETELY stock copy of the game with no 1.1 patch, no foundation, and no mods. Just in case someone would like to walk me through step by step.