This is a relatively fresh install. Anyway, no matter what GTK+ theme I select (with Sonar and oxygen-gtk also being available), it always defaults back to Raleigh. I’ve tried restarting x, logging out and in, rebooting, and reinstalling oxygen-gtk to no avail.
If it matters, I found that qtcurve-gtk2 and qtcurve-kde4 weren’t installed (before I did all of the troubleshooting) so I installed them, although there was no change in the situation (and neither show up as options).