That timing curve isn't helping a darn thing, but you can work around it, negating it almost completely using differential and/or throttle curve.

ameyam -

The sticky at the top of the gas section (http://www.rcuniverse.com/forum/m_8673009/tm.htm) go to that and scroll down to near the bottom of post #20. You'll see a diagram there you would do well to study for a minute. It deals directly with the problem you're experiencing. Take a few minutes and set your throttle and servo arms as close as you can to the figures as illustrated. Then try your new setup - I think you'll find your problem has been minimized or is gone completely.