MarketPress Pages Not Loading

Hi. I installed MarketPress, uploaded it and activated.I configured the store and saved but some of the pages are not displaying. The store page loads okay, as do the order status and shopping cart pages; but when you go to certain categories/products the page doesn't finish loading (source only goes as far as the opening DIV class=entry tag).

Store: -okay
Product: -broken

I've tried re-uploading all the files, hasn't helped. I also switched to the 2011 theme, no change.

Any idea? Thanks.