Getting a bit concerned about the auto box on my 2.4 v6. Some change downs, particulrly from 3rd to 2nd at low speeds,happen with a sharp jolt. During some change ups there is a momentary pause with the engine revving but no drive, then the change up kicks in. Its never been the smoothest auto box I`ve come across but this doesn`t seem right. Tiptronic feature seems to work fine. Had the oil changed about 9 months ago, so all should be well there. Any ideas?