well kind of new problem, it has done this every now and then, strangely it seems when it's been put in 4wd and then back into 2wd, could just be coincidence as i can't see personally how it could be affecting the issue.. basically its a new shape (2010) auto, when i go to cold start and pull away it acts as if it were a manual and the clutch is slipping, after a few seconds its perfectly fine and pulls like normal. Having looked around it sounds the same as if the torque converter is draining back? is there a known issue with these or any other ideas what it could be? Box works perfectly fine after the first few seconds, and no leaks.