the first event listed has a "date_posted" of "2010-01-09 07:06:46". This got me to wondering if where I placed the API key affected the returned data. It turns out that yes it does. In order to search properly, the API key must be listed last.
This seems like a bug to me. The order should not affect the results. If you don't fix it, at least make a note of it in the API documentation please.