I vote "age"

Actually, I still think it might be your hamstrings and that you should concentrating on stretching them as much as possible. But that is my uneducated guess.
Shannon, don't freak out too much about that hill. It really isn't that bad -- I still don't think it is any worse than 2nd Dug Hill and at least you aren't looking at the whole thing at once like 2nd Dug, thanks to the curve in the road. If you want a bit of an idea of what it is like, go to
www.aroundthebayroadrace.com and check out the 2005 video - at the 5:53 to 6:30 mark in the video it shows the hill. Also check out the 2006 race video (not the start one) and you will also see the hill at about 4:38 for a few seconds -- and Jutta at 4:58 in the video!!
If you want to see something really funny - it doesn't show the hill, but watch the 1980 video. First of all, it looks like it is all men, it seems that they didn't do all that much to close off the traffic - at one point a car makes a right hand turn between two runners. But most funny is that they are all wearing one of two outfits - either SHORT shorts with a t-shirt and tank top over top, or a sweat top and sweat pants with a toque! It is good for a laugh - no such thing as technical fabric back then. I sure hope people don't laugh at our videos 25 years from now!

Sorry for the hijack Shannon - but check out the videos. Maybe it will make you feel a bit better about the run. I don't think it is as hard as the Toad.