You might have it on the lat balance. Another thing is putting wash-out in the wing tips, this might help equalize the wing. If all else fails, put some heat on the left wing and twist the leading edge down a bit and off-set the roll.

Another thing I thought of... if you put it into a climb over 45 degrees does it want to yaw right? If it does trim the rudder.

Just trying to brain storm with ya