M2 Buell snapping belts?

My bud bought a use M2 with about 20k or so on it. He'd had it about a year and the belt snapped at a stop light. We replaced it and now less than 3000 miles latter the damn thing snapped again! He had the local Harley dealer set the bike up for him (new shock, adjust suspension, tune, oil, etc.) just a few hundred miles ago. Now my bud is not an aggressive rider. He has never popped a wheelie or done a burn out in his life. The worst thing he dose is let the engine lug a bit sometimes. I thought belts were supposed to be high mileage, low maintenance. Could the dealer have screwed something up when the set up the suspension?