Plaidophile

So, I just booted up my MacBook into MacOS X, nothing unusual. Except something unusual did happen:

That is, with no action on my part, my Boot Camp partition has suddenly started to mount and is browseable, and is still in NTFS format. It's cool, but also a bit annoying since for some reason Finder isn't applying my "don't show mounted drives on the desktop" option to it (notice that Macintosh HD doesn't appear); for some reason Finder is classifying it as "CDs, DVDs, and iPods." (Which I do want to appear on the desktop.)

Any ideas what would cause this to happen? I am positive I never installed any sort of NTFS support myself, and just because I've been booting between OSX and XP a lot doesn't mean that OSX should suddenly know how to support NTFS (unless there's some sort of disturbing AI engine sitting under the hood). I also don't think there were any recent system updates, at least not since the last time I booted OSX.

Maybe XP is the one that's smart and it's infected the OSX side with a mutual understanding and respect? Should I expect OSX to start to bluescreen?

Unfortunately, this doesn't even have any utility for me, since the rare times that I do need to share files between OSX and XP, I just use VMWare's shared folder mounting (and of course I'd trust XP's own NTFS driver a bit more than OSX's).

(Update: Oh, duh, it looks like it was mounted read-only, which is actually something that's been supported in OSX for a long time. So the mystery is actually "why is Leopard suddenly automounting my NTFS volume," not "why does Leopard suddenly support NTFS.")