Take a look at this article:
http://www.jpeds.com/article/S0022-3476(99)70173-3/abstract
Unfortunately, without journal access through a university/medical library, the full text costs $$, but google scholar caught this glimpse from it:
"Several recent investigations have also identified
a high prevalence of orthostatic intolerance among those with fibromyalgia. ... "
so it does link CFS, EDS, OI, and fibromyalgia (and is by Rowe).
Here's another one about JHS (the umbrella under which EDS falls) and fibro:
http://www.jpeds.com/medline/record/ivp_08937524_11_39
EDS/JHS are definitely known to be associated with dysautonomia/autonomic dysfunction. If you have a rheumatologist, s/he should be able to evaluate you for JHS/EDS. From what you described ("joint over flexibility" and "over flexibility in veins"), I think that's the missing link that I wasn't getting from how you were getting from fibromyalgia to OI. I'm guessing that is what you may have heard/seen Rowe referring to: a link or correlation between fibro/CFS, EDS/JHS, and OI/dysautonomia.
For more information on EDS/JHS, you may want to start here:
http://www.mayoclinic.com/health/ehlers-danlos-syndrome/DS00706
http://www.reumatologia-dr-bravo.cl/patients/Dysautonomia.htm (Not a US site, so pardon her English in places; still worth reading because she focuses on JHS+dysautonomia in particular.)
http://www.medhelp.org/forums/Ehlers-Danlos-Syndrome/show/417
http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0002439/
Feel free to ask more questions here, post another thread, or send a personal message to me directly anytime. I hope this information is helpful to you.
-Heiferly.