I am now receiving a whole new error on the pp_confirm.php page which states:
Warning: session_start() [function.session-start]: Cannot send session cache limiter - headers already sent (output started at /filepath/wa_evaluate.php:1) in /filepath/WA_eCart/WA_eCart_Definition_PHP.php on line 480
I seem to be finding that this solution is not so easy to install, for me anyway.
Many thanks again with all your help.