MarketPress - cannot get to individual items page

Hi Aaron -

I'm setting up a test store with a Sandbox Paypal Express Gateway.
http://test.skyrocket.me/store/

Everything seems to work except for the ability to pull up an individual product page.
http://test.skyrocket.me/store/products/push-and-pull-activity-gears/

I get a 404 error for all of my individual products, even though they show up in the search. Thoughts? Could this be a permalinks / htaccess thing?