Thanks Jason.
I found a more recent thread than the one you posted from Paypal MTS, (which doesn't work for me as it will not accept my login when attempting to create an sandbox payments pro account).
for the record, the url is...
std_adp.php?p_faqid=738&p_created=1232537554&p_sid=oPse6RGj&p_accessibility=0&p_redirect=&p_lva=&p_sp=cF9zcmNoPSZwX3NvcnRfYnk9JnBfZ3JpZHNvcnQ9JnBfcm93X2NudD00MTcsNDE3JnBfcHJvZHM9JnBfY2F0cz0mcF9wdj0mcF9jdj0mcF9zZWFyY2hfdHlwZT1hbnN3ZXJzLnNlYXJjaF9ubCZwX3BhZ2U9MQ**&p_li=&p_topview=1
thanks for the second link, this page too seems to have been changed since the posting.
I have made an enquiry through paypal mts, let's see what happens next !