Cart page isn't updated when products from upsell block are added to cart

Hello,

in the cart page, I have an upsell block with products in it.
when I add a product to the cart from the upsell block, the ajax cart block is updated, i get all the ui messages, but the cart page isn't updated. Then when I click on the checkout button, the products arn't there (it takes the current info from the cart pane).

in addition once I click update cart - the upsell block disappears.

Thanks