Marketpress new products hidden

I've just added about 80 new products but none of them are showing on my main shop page. The page is a custom template but has no product filters, and nopaging=true. The products are all there on the backend and showing as published.

I've tried refreshing the browser and clearing the cache but that doesn't change anything. The new products are all from Dorothy Perkins, but only my original 3 lines from that store are showing.

I'm stumped. Can anyone suggest what I need to do to make them show?