Here is another link with a broader overview about conditioned crawlspaces and the inadequacy of current code. I think it's pretty good information.
http://www.buildingscience.com/docum..._download/file
Best,
Edit:
Hey AC, I was starting to feel bad that this damp wood phenomena might affect you directly. But the more I think about it seems like you might be safe. I'm basing that on the fact that your heat source is directly coupled to the floor. So there is a good chance that the closeness of that heat source to the unprotected edge of the joists will overwhelm the normal cooling effects. I hope so.