You know I noticed the same thing recently. Just did a fresh O.S. install with Vista and MM, not the beta, and I couldn't embed the cover art through auto tag from web. Thought nothing of it because I tried it through trixmoto's batch art finder script and worked fine. But yeah, noticed that yesterday as well.

Maybe you have no modify rights on the tracks. If 2 different programs can't do it I would look at the files being the problem.

I used to have no issues with this, but lately I've noticed that whenever I try to embed album art into mp3s which have other images embedded within, they don't take.

All other metadata is changed according to how I set the properties, but album art isn't. I've even tried to use MP3Tag, to no avail.

Any help is appreciated!