Well, well, well! I have found the culprut to my crazy awful headache! When DP and I bought lunch on Sunday, she had orderd a Coke and I a Sprite. Well upon returing home she discovered it was rootbeer (she HATES rootbeer), so I offered up my clear bubbly beverage for hers. I found out that Barq's rootbeer really does have bite! I had nooo idea it had any caffeine in it (while growing up, rootbeer was always on the parental approved list). It is the ONLY rootbeer which contains caffeine, hence the catchy slogan. Yup, I'm a little slow. No more Barq's bite for me!