I've been using baseflight for a while now, no problems. Until one day however after not flying for a few weeks, when I pitch forward on the transmitter, in level mode, the quadcopter tilts about 20 degrees and stops. Its hitting some sort of end point. When I go backwards, the stick is much more touchy and goes back much further. Rolling left and right there is no problem. Baseflight shows that the pitch stick moves an equal quantity both ways. Also in acro mode, it tilts forward very slowly, but tilts back quickly, and I am stumped.