Actually I'm not surprised that you are doing so well with your gut symptoms when you can tolerate those very nice doses of chelator. You are apparently well on your way to recovery. Good for you after all you've endured for many years! Many people, including autistic kids, report an improvement in gut problems after many months of chelation.
However in the large Yahoo chelation groups for adults and autistic kids, it has been reported countless times that DMSA is difficult to use in the early months when there is a history of gut, especially candida, problems.
Cutler has acknowledged this and provides tips for dealing with it; however, now that DMPS is more readily available than it was just a few years ago, it is so common for the very sick members to just use DMPS in the early months.
Btw, I've done fine on modest doses of DMSA, however, a close female friend can start to have problems if she uses DMSA more than once per month or so. She does well on DMPS + ALA.
It was kind of you to share your thoughts and experiences with our very sick members. I've had similar experiences with my doctors over many years. So many of us in detox groups are frustrated with the impotence of our many doctors.