Ive only had the mini Z for a month now and it has thrown the blade drive belt 3 times. My son was cutting the first two times and said he had gotten up with the blades engaged and when he restarted after the shutdown the blades would not engage. A quick check under the deck showed the belt jammed under the guide on the left side pulley both times. I went back to the dealer and had them reinstall the belt ($26 the first time/ $115 the second...they bent back the metal casing on the pulley covers citing that as the reason the belt was thrown/they had apparently been slightly bent down when going over a curb). On the third time, I was mowing. I disengaged the baldes going over a walk and reengaged on the other side...only they wouldn't. Once again the belt had train wrecked over the guide. Fortunately, we are a new company and have been able to work around this with our light load for now....I was wondering if this has been an issue before and what to do....the dealer has loaned me a 42" and is holding mine till a rep can look at it....is this a common problem?