Thanx for your reply Abby, the muscle tension is a good one, since tight muscles in the neck/ shoulders/ upper back area can also create headache.
I thought I was loosening up the muscles with my warming-up exercises but maybe that is not enough.
About the coffee, yes that definitely goes two ways in my experience.
14 lbs down, 22 to go
Female 37 yrs 5 ft 7
Start weight 9th December 2011: 190 lbs
Current weight 2nd March 2012: 176 lbs
Inches lost around waist: 3
Goal: 154 lbs by 1st of January 2013
How: Portion control, shun liquid calories, snacks and junk food, running 3 times a week
Why: I want to get in better shape physically and mentally