I raised a ticket but thought someone may have come across this issue before

When a customer places an order via Paypal they don't have to be registered. Paypal parses the information back to ASPDNSF and creates an account with no password and the IsRegistered field set to 0. I have a customer that has 20 Paypal orders but now wants to use a credit card and create an account with a password.

When the email address is entered it says that the email is already is use. I have tried every way I can to try to have the email accepted but will will not work.

The global config AllowCustomerDuplicateEMailAddresses is set to No but would this not block any further paypal orders? If so do you know of a way where an email address can be the same for two accounts where the only difference is the IsRegistered set to both 0 and 1