Engine stalling and dragging at low acceleration

Hello,

I am currently driving a 2005 Nissan XTerra with approx. 55,000 miles on it.  Recently, the engine stalls and drags while I am accelerating at very low speeds.  However, once I pick up speed and get rolling, the stalling and dragging stops and it performs normally.  I have taken it to the dealer and they weren't sure if my transmission was bad or if there was some kind of mechanical issue going on.  The car used to shut of while I was driving periodically but that stopped completely after a vehicle recall repair was completed on it.  I would appreciate any insight you might have into this kind of issue.