It sounds like the same problem I had/have. On mine it's the center bearing on the driveshaft. It's only noticible at low speeds, comes and goes, and kinda sounds like a high pitched (but quiet)rubber squeal/squeak sound.

They lubricated it the first time I brought it in and replaced it the second time. The sound has come back with the new one though. Hasn't caused any problems yet, just annoying. I plan on taking it back once the weather gets a little better here.

- Jason