success page blank with WorldPay addon

Hi peeps,

I have looked through the Worldpay thread over a few days and can't seem to find what I am looking for. I have also been back and forth with Worldpay support team and they have been helpful, but the issue isnt solved.

Basically, I have the whole site ready to go, the worldpay integration works well, payments go through, orders added back into zen cart admin area, emails all go out, but... the callback is apparently working fine, worldpay guys say its fine, but there is apparently some problem on zen side displaying the page that says: thanks for your order, etc...

the rest of the callback part works fine, I have my header, navigation, footer, links, images, etc... except there is a big main body blank area that says nothing.

any ideas?

thanks in advance