Bump!
I bumped this thread to add that the lower boiling temperature can make a big difference if you are either (a) decoction mashing, or (b) using a decoction to bring up the temperature on an undershot infusion.
I ran into this this weekend. I used Beersmith to figure how much of my mash to decoct and boil to hit my conversion temperature, and got confused when I undershot the mark by almost 10 degrees.
In Denver, at 5500 feet (my approximate altitude), water boils at about 202 F, that's why. I'll remember to make this adjustment next time.