I can't help but chime in here. about six months ago I entered a tremendously stressful new stage of work, and subsequently I started having all kinds of strange health problems, apparently now all related to GERD. I have panic attacks occasionally, and apparently it's not uncommon for GERD to go together with these.
In short, I had tons of test run, from ultra sounds to MRI's all coming back clear. As one Dr. explained it, the GERD can affect the throat, which affects the ears, which in turn can cause dizziness and lightheadedness. I've since noticed on a regular basis that the funky taste in my mouth and the tightness in my throat tends to correspond with my ears feeling somewhat tight and my head spinning.
So in short, yes I suffer dizziness with GERD and this is apparently not uncommon.