Airbox backfire and stall on throttle blip

Its an 03 with 12k miles
Dual holeshot high mounts
TRE
power commander
I have the idle set at about 1300 rpm.

The PO stated that the PCIII had a custom tune - Due to the flat spots at 3k and 8k, i call his bluff.

Once in a while on throttle blips, i get an airbox backfire. I read all bout it on here, and i have done the pair disconnect. After the pair mod, there was a signifigant reduction in exhaust backfire, but the airbox backfire is still there. It only occurs at the slightest throttle blip when the bike is warmed up. While coming up to a turn this morning, i down shifted from 3rd to 2nd, I blipped the throttle before dropping the clutch and it backfired and stalled. I would assume that its a little lean down low, and a new tune will clean up the powerband, but im thinking that the backfire may be a sign of a valve adjustment in the near future. Any input?