A family member has this. I may be wrong but I seem to recall something about this symptom on the List [something other than the story by the Listmember who, as a child, used to put mercury from broken thermometers in his mouth and push it through his teeth], but I cannot find anything significant in the achieves. She, my sister, has so many medical problems it really isn't funny, and her main doctor seems to be Dr.Koop.com, but I told her I would pass on anything I could find out. [She is also caregiver for our mom, who is in a really terrible stage of Alzheimer's right now.] THANKS, BBA