You have probably tried this already... am I right to assume that you have tried this from different PCs/browsers etc.?
Have you attempted to recreate the problem on Firefox?
The results are the same across all browsers and computers. I've emptied the cache several times - the chart will not update - Not since April 2nd, 2012.
New dashboard static images will not generate, either. It's been over 24 hours since one of my new dashboards has been published and viewed online, and there are still no static images.
This is beginning to be a large problem here.
The problem is fixed. Your static images should be updated now, including static images for the views you published recently. It was a problem on our end. Super sorry!
Let us know if you run into any more problems.