My CX2 starts off flying well ,Nose Straight}Trim Center as time goes on my Rudder trim needs more n' more left -till by close to end of pack :I'm full left trim to keep nose straight. Is this normal?Iv'e adjusted the gyro Trim so it doesn't tail wag when doing a 1/4 turn and stopping. Its really pretty good for a little while, I wonder if I should just make it start off with a bit of left in nose to compensate for the last 1/4 of flite.? What do you think.....