So. I might have solved it. I disabled the "additional data from the internet" setting, then selecting "apply media information changes" or whatever that setting is called, under the button in the upper-left. Then I set to download metadata from the web again, and so far it seems to work fine.
I seen a pattern here. It basically "loops" the downloading of certain metadata every time I run Windows Media Player. The same albums/songs gets their metadata downloaded all over again. It consumes up to over a gig of memory. But now it seems to be solved.
