This has happened to me also. I'm still using the radio and it works perfectly. I have flown three different Ergos,a Nexus and now fly a JR Venture 30 and JR Voyager 50 with the radio. I talked to Hitec about it around a year or so ago and they said it was a factory defect (I think, it's been a while since I spoke with them) and they would fix it if I sent the radio in. I never did send it in, I just leave the max pitch at 99% and fly with it. As I said I've had no problems with it and before every flight with my planes ( Airtronics computer radio ) and my heli's ( Hitec radio ) I always check all my control movements and throws and have not had any problems.
You can go to www.hitecrcd.com and get their number and give them a call if you want.
Good Luck