NAG1 Transmission won't upshift!

[goose]

Not sure if this is the right forum to post this in or not... anyways, my 05 Magnum RT started having transmisison problems the other day. It refuses to upshift until the revs are way too high for the throttle setting i.e. even when I'm just barely on the gas it won't shift 1-2 until 3500 RPM and 2-3 until 3900 RPM. 3-4 happens at about 70mph so I only did it the one time (the speed limit for the road I was driving on is way lower than that).

The trans always used to work fine (I've owned the car for over a year), however the problem appears to have started occuring right after I uploaded a "canned tune" to the car from the Diablosport Predator I purchased recently. I've asked Diablosport for help/advice but none has been forthcoming even though I've bugged them for about 2 weeks now. The trans fluid level is within spec. First thing I tried was resetting the transmission control module, first with the Predator and then with a hard reset (unplug battery) to to avail.

Anybody have experience with these trannies?

[JVMopar]

Either reflash it with the stock program, or take it to the dealer and have them reflash it with the stock program.