Are you taking the supplements strongly recommended by cutler esp Zn, Mg, C & E?
Some need to take the chelators more frequently--DMSA every 3.5 hrs. While your 12mg dose is a good starting dose for many we hear of some who need to start even lower.
Are you sure all of the Amalgam is gone from under crowns? We occasionally see cases where remaining Amalgam causes strange headaches during test rounds of chelation.
You'd get much more responses at the cutler groups on yahoo: frequent dose chelation, adult metal chelation, etc. He stops by occasionally to post.
Joe