I indeed have version 4.1, had no idea. So I'll switch to 5, maybe that helps. So much for now and thanks.

If you look in the HELP menu item you will find ABOUT. What version do you have?
I am not seeing the behavior you mention .. waiting for Lowlander. Is this reproducible? If so give exact steps
I have only 150K songs but it works well for me

When I try to delete say a whole album of songs in one sitting, it usually takes like three clicks on the delete button. What is far more bothersome is that the next song on the playlist, the one after the deleted ones, automatically starts playing, so I have to stop it.
I believe I have version 5, but can find no "about" button or anything else to verify.
Also, I think MM having no stop button but just a play / pause one is intended and no glitch?
Sorry for one more question - I have 70.000 files now - has anybody ever experienced, apart from what the company says (more than 100.000, I think) how many MM can really handle?
Thanks for your patience and maybe help.