My 2005 has a similar flat spot, but it is much less noticable when I am running TOD, consequently I've been running bmc/compwerks/TOD for a few years now. I have SAI removed and blocked, and the O2 sensor is disabled physically and in tuneECU. Oh, I have done a lithium battery with a direct wire in for the starter and compufire regulator/rectifier, what a difference those mods made! Bike starts like a beast and I haven't burned a stator since I did the mods, though it's only been a year.