After checking your servo travel and speeds as suggested above, make sure you "dynamically balance" your aircraft. Your wings might weigh the same, but that doesn't mean your plane will be balanced under flight loads (G's).

Reference Peter Goldsmith's Trimming article in MA (Scale Aerobatics Feb and Apr 05) for details.

Reference Post #5: http://www.rcuniverse.com/forum/m_28...tm.htm#2819925

It is best to run the whole trimming sequence, in order, but here's one step.

Here's a quick overview: Climb to an altitude of 500 to 1000', go into a power-off dive, 3 to 4 seconds, then pull hard (on low rates, ~15 deg elev. travel) to the horizontal...your wings should be level when you reach horizontal, if not, add weight to the higher wing. Repeat until satisfied.

Good luck and keep us updated!