Winglift,

It could be an elevator half is out of adjustment or it could be a wing low entry. Both can create this problem. Go to this link http://www.nsrca.org/trimA.htm and print a copy of the chart. You do not have to do all of them but the first 5 or so are important. Instead of doing a loop, do vertical pulls in front of you and directly in line with you to the side, so you can clearly see what the model is doing. Also the vertical dive and pull out will tell you a similar tale.

Marty