Can an aircraft or helicopter run into its own wake vortex?
Helicopters are not easy to fly - whether full-scale manned aircraft or RC models. I would bet that your issues are more related to pilot error than any fault of the machine (other than the fact that it is a helicopter, and inherently unstable).

That said, almost any aircraft can be maneuvered in such a way as to encounter its own wake, and the helicopter is no exception. In fact it's much easier do to this in a helicopter than in a fixed-wing aircraft: A condition known as "settling with power" (or "vortex ring state") can occur when a helicopter descends into its own rotor wash, e.g. by descending directly vertically in calm air. The results of such an encounter can be "unpleasant" - a number of helicopter accidents have been attributed to this sort of encounter.