Yes.
Most modern Garmin Edge devices (the 510 included) use barometric pressure for determining elevation. Wind gusts cause pressure changes (edit: or, more likely, pressure changes cause wind gusts) which convince the Edge that the altitude is changing.
I don't know whether or not that's entirely responsible for what you're seeing, but I think it is certainly plausible.
Last edited by cplager; 10-07-13 at 12:39 PM.