ok, didn't know that the file monitor does this
but there's a difference between folder monitoring and the kind of auto-add i mean! i suppose the file monitor does his scans during the start phase of MM, if i copy a file into my musik folder, he will not notice it until the next start. if i play that recently copied file it's still not shown in the library! but i want it to be there instantly when i play it! (i barely turn off my pc and MM is always in the background, so i don't start him very often)
it's not that high priority, but the effort to code it is low too i guess
btw. there's another missing feature that came in my mind...

it would be nice if the currently played song gets highlighted in the library list (on the right side)
it's a minor one too, but it would be nice

(wmp9 does this!)