Did they rule out Benign Paroxysmal Positional Vertigo (BPPV)? That's what I have. Here's a website with info:
http://www.tchain.com/otoneurology/disorders/bppv/bppv.html
Hope you figure it out. I can't do much for my BPPV but these stupid head exercises. Fortunately I only get the vertigo (dizziness) a few times a year.

Hmmm. I'm not sure, actually -- that was a very informative site -- thanks! She only said at one point that I didn't seem to have "positional dizziness" which didn't mean anything to me at the time. Maybe this is what she was talking about, but I honestly don't know. If I don't get better with the meds, I'll definitely ask about this.