Everytime I advance the throttle the entire rear fuselage and tail section twist. It doesn't seem to affect it's performance but I can't figure out a way to stop it. Anyone else?

I had this problem until I added the triangle stock down the rear of the fuse. Did you install that? Like this [link=http://www.happyhangar.com/displayimage.php?album=80&pos=11]Tail Flex[/link]

They have triangle on them stock.

Only if you glue it on

Mine is scratch built and I tried to leave everything off that I could to save weight. The wing struts are not needed but the triangle has to be there if you don't want the tail to twist all over.