[Boog]

Brad I have the same occurance with my 2000 GMC. I've had the truck for almost 3 yrs and it's done this maybe 5 times. When it happens it feels like the brakes are holding it back but I believe it's more like the trans is not downshifting to 1st gear like it should. Sort of like it's starting off in 2nd or it's in 2 gears at once. What I found to work is as soon as I feel it doing this I let off the gas for a second and push it again. When I do this it restarts in 1st gear as it should. No noises or check engine lights accompany this weird start. It only happens when taking off from a stop. Always was fully warmed up. Mine only has 150,000 miles on it.
I've hoped one of our tranny tech members might have some experience with this.