Marketpress Shipping Missing

Hi,

I have had recurring problems with the shipping line of the shopping cart disappearing. I fixed this a couple of days ago by re-uploading the plugins-shipping folder and that fixed it but after moving servers, the shipping is missing again (doesn't appear even though it is set in store settings (flat rate) and prices have additional shipping costs).

I tried re-installing the cart but to no avail.
I tried deactivating and re-activating. No good.
I upgraded to newest version of marketpress lite. No good.
I am using wordpress 3.1 and the latest version of marketpress lite.

Mark