Hi Dave,
What are you using to balance and find your CG?
Try the Vanessa CG Machine. Cheap, Easy and accurate.
You might find out that your not that far off [8D] or you might find out you're further off than you thought too [:@]. either way this method is very accurate.
Here's the link.
http://www.rcuniverse.com/forum/m_70.../tm.htm#708060