This is similar to another issue with the Facebook Like button. But this is for the Twitter Tweet button. On my site, the Facebook Like buttons show the count, but the Twitter Tweet button stays at 0. I've searched for a solution, but there isn't too much written about this. Most people seem to be focused on what kind of browser, but this happens across all browsers for me.
For reference, here's an example of what URL the Tweet widget shows:
Is this related to the use of the Shorten module (project/shorten)? Has anyone solved this issue?