Errors in shop pages, theme incompability?

Hi guys, just tried out Marketpress and though it installed fine and admin options work, the actual shop pages all give the same errors, see http://flexiwaysolar.com/store/products/ for an example.
No product shows up, and it seems that the theme somehow is not compatible?

I know that I will probably be sent to the theme support (and they will likely send me back), but do you have any idea what could cause these errors?

Thanks!