Hi Dr Byte,

Thanks for the response.
I have had a look at the files in question and checked for any spaces at the end of php tags, removed any that I found, tried using the classic template instead of the one being used on the site and still got the same error message.
I reinstalled worldpay using the most recent download available just in case something in there wasn't working correctly.

Im basically at a total loss as to what to try next

Cheers
Brian