Strange Dotted Line At The Top Of My Products Pages

Hi,

I'm setting up MarketPress for a client and it's working fine except we've noticed a really weird dotted line across the top of all our product pages. They don't appear on any other posts or pages on the site so it's MarketPress specific, and occurs in all browsers.

Any ideas where it's coming from and what might be causing it?
http://www.modelflyermagazine.com/rc-electric-flyer/store/products/current-issue/ It's at the top, behind the buddypress admin bar.

Thanks

Justin