The Dataset name displayed on the Main Menu does not match the name of the dataset I am running.

I've heard of this display error before in MYM with the dataset showing a different name than the one that is actually loaded. It's just a display error which I think can be fixed by just loading in a different dataset and switching back again. You could also try running MYM directly from the DOS prompt and loading a specific dataset by typing "MYM [dataset name]" - no brackets. Try directly loading a different dataset, exiting and then directly loading the current dataset again. Once you get it "right", it should stay that way.