Sounds the same as my blade. It gives me the same aggro. Fine when revving when sat on the driveway. When moving and accelerating, it hesitates at 3500, until I get it past that, then it shoots off again. I've found that running on '98+ octane fuel helps, or adding octane boost to my fuel makes alot less problematic. It's been looked at to try and find the route cause of the problem, but my motorcycle dealership never solved it and I've learned to deal with by paying more for premium fuel/octane booster.
I always wondered whether it was my aftermarket exhaust causing the problem (as it's pretty much the only thing I haven't tried) Is yours standard or aftermarket?