Thanks a lot William for your really good explanations.
You'll never be too wordy for me, what i like is detailed explanations just like you did because i am considering myself still a beginner. When i ask a questionn, i read everybody's reply twice or sometimes even more just to make sure i really understand eveything. I have never reallly understand what wash-out was before you explained it to me. I know there is a wash-out on my wing (Mid-Star 40) because it says in the manual that it has a "built in wash-out" and that's all it says. I don't how how many degrees. Since there is no difference in roll rate when i change the aircraft speed, like you all said, i guess my wing is warped. I know now that my aircraft is rolling to the left because i just checked my ailerons on the wing. So i'll give it a try and do like you just suggest me William and "twist the right tip down" a little bit.

Again thanks a lot...