I have the same problem, stuck at a steady 110%, even after a full day of rain.
Switching between Zimmermnan and ET back and forth forces a manual update of ET, but no automatic, daily update.
I can confirm that weather script is set to point to weather.opensprinkler.com.
When I have time, I will go the factory reset route, or is there any indication this issue might be solved through a software update?
(the question being: are all users affected, or only the ones with a funky setup (mine being pretty straightforward, un-funky), and what would be the common denominator for the affected systems? – but perhaps that is too much hassle to figure out, and heck, what is more fun than reprogramming your sprinkler setup? ;))