Another convert to this fantastic plane. Your CG is to far forward. I have a similar problem with a full tank of fuel. I'll be switching over to a NIMH 6 volt flat pack saving 2.5 oz of weight over the NICADs. This should move the CG aft by 1/8 of an inch. I'm also considering swapping out engines from the .60 installed to a .90.
I flew my airframe today in 15-22 mph of wind and was able to maintain 0 ground speed for extended periods of time. Harriers from 300' AGL showed no wing rocking or wing drop and all landing were performed with no runout. I also got the plane to go backward in-flight while maintaing a 60 degree AOA.