I've sent this to wp support. When I get an answer, I'll post it here.
I have three blogs registered under my user name. When I click on stats for politicaldimensions.wordpress.com, the daily graph doesn't load. It times out after 15-30 seconds. (I'm on 1.5mbps DSL). On an orange background (where the stats would be), the error shows in the middle, one line that says, "Loading wp/includes/charts... timed out"
If you want the exact error message, I'd have to type it in. I can't copy the text from the orange background.
When I click on the "Week" or "month" tab above the orange section, those stats actually do display properly. Clicking back to the "day" tab brings up the orange screen with error message again.
This doesn't happen with the other two blogs I have registered under this account (mentaldimensions). When I "switch blogs" on the stats page, the daily chart comes up.
This started earlier today.