The citystats section is timing out on any city with a non-trivial amount of data.
For example, when I go to see Seattle:
If I click on the stats icon, the spinner appears, and then 30 second later, it finally times out.
I see that the request for chart.json times out after 30 seconds.
I can go to some of my cities that I only have a few activities on and see stats, but cities with large number of activities seem to break.
My profile link :