never heard of this
Check:
http://www.rfsafe.com/ftopicp-958.html
http://www.mobiletor.com/2008/01/21/mobile-phones-affect-peoples-sleep-and-causes-headaches/
http://blog.wired.com/gadgets/2007/06/study_gsm_900_p.html
That gives you a little on both sides. I would guess that some people are just more sensitive to things in their environment.