I've just installed Oneiric (64-bit), and immediately after installation I followed this guide to get the Gnome Classic interface (I've tried Unity... I really wanted to like it, but it just never stuck). It seemed to go ok, but when I'm in a Gnome Classic session, I have no volume control applet, and there doesn't appear to be one in the Add To Panel list.

The volume control is there when I'm in a Unity session with the same user. This may be similar to this question, but the circumstances seemed different enough to warrant a new question.