First off I would check to see if the KLEEN air has been blocked off. I would assume that it has been if the bike has been tuned on the dyno, but I've seen stranger things. The other thing to look at is leaks in the exhaust system. The Akro doesn't use any clamps to hold it together, just springs. It is possible that your exhaust has flexed or was never slid together just right and is sucking air on deceleration causing the pop. If you have to you can get some sealant from Akro, or from the parts store, and slip all the joints apart and put alittle sealant around them and slide them back together. This should stop any exhaust leaks.
If it's not the KLEEN air system, or the exhaust, then I would start checking your PC map.
green 10r, Akro EVO 2, Hyperpro rsc, tre, pcIII, Puig DB, K&N, Purvision HIDs, Speedohealer, GONE
08 Ducati Hypermotard S
08 Kawi Concours 14, Area P full sys, PCV, Flies out