Stephen,
You may want to get your stat or something checked! Going up those hills, as fast as you were, with the A/C on, you should have been running hotter than that!
I think you could be on to something there - although, I have a new rad and fluid courtesy of the tranny shop that punctured it when I was get the 2nd gear synchro replaced.
When I was sitting in Vancouver traffic in the heat today, the needle would go up to about the half-way mark but quickly cooled again when I started moving.
How could I check to see if the needle is really true?
Rob