Connecting to Paypal UK Web Payments Pro

Am trying to get e-cart 4 connected to Paypal UK Web Payments Pro. Initially I had incorrect log-in settings and used the de-bugging bindings suggested.,- led to an "incorrect vendor account " error message. contacted paypal and followed Paypal's instructions to getting correct username/vendor/password/partner settings. unsuccessfully it seems.

having been told to go to API credentials settings in paypal and select the payflow settings, i applied them and got same redirect to checkout_failure.asp (tho this time without any response binding information showing up?)

contacted paypal again (and sent them confirm.asp page) who say (in broken english)

"From the code in the body of the email, The API details you are using here is the API signature, the details entered are not correct, I would recommend contacting your cart provider to find out exactly what they need to proceed. From your original email the items require where PayFlow credentials, where I provided a video guide to obtain them, however the details in the body of the email indicate that you are using an API signature which is different to PayFlow credentials.

I have attached a guide below as well on how to obtain the API signature details, however you will need to contact the cart provider to find out exactly what information they need, whether it be PayFlow credentials or API signature credentials.
std_adp.php?p_faqid=737

Could you put me straight on exactly which items of information i need to be putting in each field? (confirm.asp page attached)

thanks