--unfortunately, dizziness, vertigo, unsteadiness and the like are common side effects of Gabapentin (and, in fact, of most of the anti-seizure drugs that are also prescribed for nerve pain reduction).

Neurotalk has one of the biggest and most active RSD/CRPS communities out there, though, and a very extensive database about the condition and its treatments, so I'm sure you're going to get all kinds of advice/information over at that part of the board.