By "jerking ahead", does it feel like the front wheel is lifting up a little bit? If so, put more weight over the front of the bike. I know, hard to do when you're climbing steep grades and the natural response is leaning back to get leverage at the pedals.

I only ask because it is a problem I have with some bikes. If the bike is just a little bit too long, the steepness of the pitch seems to accentuate that you are properly weight-balanced over the wheels.