I have a Bionx 500D on a recumbent and every once in a while the wheel starts making noise and does not want to assist. This has happened 2 times after hitting a bump and today after coming down a hill with brake lever in regen. I shut the system off and then back on and it was ok. Last time I had to put in assist level 4 and pedal hard and then it growled hard and then acted normal for the rest of the ride. Contacted Bionx since my Dealer went out of business for some advice but all they said was find another dealer and take it in. If it is not doing it at the time then nothing will be done. Has any one with the 500D system experienced anything like I am describing??????