Motorcycle Repair: VRSCDX Night Rod Special, vibration noise, czech rep

Question
I am an owner of the above machine since April 2007, VIN No. 5HD1HHZ147K8O7313. After the run-in period (of low rpm), the vibration noise appeared at engine rpm 3500 and 5000, under acceleration. The bike was checked by the local dealer (Prague, Czech Rep.) under warranty and the rear fork pivot and bushings replaced, but the vibration persisted, although somewhat attenuated. Recently, another Night Rod Special has shown the same trouble even more vigorously and the dealer observed on a jet-dyno that the vibration is caused by the secondary drive belt top (tension) part that, at the above-mentioned rpm, develops a wave that touches the upper belt guard. At the moment the dealer waits for the Europe chief dealer response. He likely inquires the manufacturer in the USA.
Question:  any solution to the above trouble in the US or by the manufacturer?  The VRSCDX are in production for almost three years and I do not believe that only two, here in Prague, are faulty!
Thanks in advance for your response,
best regards,
Jan.

Answer
If the belt is hitting the belt gusrd then I would check to make sure the belt is adjusted correctly.It should have enough tention on it to keep it from vibrating like you stated. I have not heard of this problem here in the US.
Good luck and happy riding
Mike