MarketPress Products stuck in loop

When I click on a product for more details on my site it seems the products go in an infinite loop. I've tried like other support articles say to comment out //add_action( 'option_rewrite_rules', array(&$this, 'check_rewrite_rules') ); but with no effect.

Can someone look at my configuration and tell me what is going on?

click on any product for an example: http://www.traditionalstudies.org/store/products/