Gregg, I started this post agreeing with jules' "go to a doctor", and then noticed your Nov.
2005 registration date - which made me view you older posts. I suggest you click on your profile, and reread all you posts since you joined this forum in Nov. 2005. And some of the to responses to them. You're still dealing with the same problems you had then - intermittent periods of feeling horrible interspersed with others where you feel great.
You never had a PSG.
Your oximeter observations, Dec. 2006:
viewtopic.php?p=133284#p133284
And yet, 7 months or so later you sold it because you'd been feeling so great - without any cpap therapy.
Perhaps you should do your own, systematic sleep studies at home, like ca_hosehead and tssleepy have done.
You
may have breathing problem - the reason I say this is that when your machine was on auto, it reported flow limitation - and UARS is not necessarily accompanied by major oxygen desaturations.
Could you be having allergy/congestion responses? Have you tried nasal irrigation on a daily basis? That's a very low tech solution (
http://www.neilmed.com) but it may help with your breathing.
Have you checked you nutrition? Do you eat a balanced diet? More specifically, might you be suffering from vitamin b12 deficiency which may cause debilitation similar to what your describing?
Have you considered
food allergies?
O.