so it's really funny, but I had the same problem with (I'm assuming) nautilus. I hadn't done program updates in a good 2 months (I was using Avant window navigator + terminal, and no longer had a use for menu icons). I did a whole bunch of updates, and suddenly I can no longer mount my NTFS or FAT partitions from Nautilus. I have to open Thunar, or mount them from the terminal. Lame.
side-note: fun is explaining to a recent Windows to Linux convert that on window managers such as Openbox or Fluxbox, you don't have a menu button. My boss doesn't understand the concept of open window space, so he can never bring up a menu.