Hello Brenda & Mark:
@Brenda: I can confirm B6 seemed to have helped considerably with my ME (and I recommend anyone trying vitamine-supplementation - in large doses - to do a search with "Orthomolecular" (+ one's interests possibly) and do some reading, if one hasn't done so already) but can also confirm - years and years of taking a considerable amount - that it did not make me dream.
Mark: But what strikes me is the "not dreaming" thing. I didn't dream from 1995 to about 2005, during the time when I was fatigued and sleeping 12+ hours a day and unrefreshed. It's clearly an interruption of ability to enter certain alpha/beta wave states (I know that's a bit vague) and this could explain so many of the classic CFS symptoms - muscles etc don't get into their rest/recovery state, we don't process new memories properly hence the brain-fog. My chronic neck/back pain disappeared after the first good night's sleep - and I dreamed, slept for 6 hours, and woke bounding with energy! (That new bed only lasted me a week though! ).
Anyway: I think the above experience gave me a key insight into the sleep-related dynamics of CFS, and dreaming/not dreaming seems like an interesting and important subject to explore - a poll might be interesting...
@Mark: Seems a good idea + observation to me. I'd be particularly interested in knowing what percentage of people with ME stopped dreaming while doing it regularly before falling ill with ME.