Transmission jerk/jolting shifts or Engine Boke down ?!

[Sushiyummy]

Just this morning while city driving at 40mph/2k rpm, I'm slowly accelerate and it happen. It acted like engine want to bock down. I'm release the gas and try to accelerate it's normal. but it happen again like 5 minutes later.

 

[MMothersell]

Mine has done that since new. It's always at about 1200 RPMs when accelerating gently. if you keep your rpm's up it won't do it