That is the solution to your problem: trim some elevator down and fly her mostly inverted.

It sounds like a top heavy design. A quick experiment would be to mount some weight below the plane, just to see if it improves the roll stability when right side up.
Here is a top heavy design of mine. I flew it a few times, then "decomissioned" it.
The 24 inch span was overmatched by all of the bulk and side area that sat above the wing. I never did get the nerve to fly it inverted, but maybe that would be fun to try next summer..?
http://www.youtube.com/watch?v=eGZu4...G7PvspskjQLq9A

Ya should have tried inverted.... if similar to my Seagull Spacewalker, inverted suffers no adverse rolling. All the top heavy is then on the bottom.

You have amazing eyes !!

At that speed and size, I wouldn't be able to recognize top or bottom,.............nice flying!

Thanks, but the camera "footage" makes it look harder to see than it really is.
I wonder how it would handle if an inch or 2 was cut off the fin...?