Problem combining ePrint and snapfish accounts

I'm having problems logging into ePrint because the login gives me a popup saying: "It looks like you have a Snapfish account and an ePrintCenter account that use the same address. Let’s combine those accounts to make it easier to access both services."

I put in my Snapfish password, but this is declared "Invalid". I've reset my Snapfish password to a new one, but it still won't accept the password. I've tried clicking "Forgot Password?" in the popup and following the password reset procedure there, but the popup still won't accept my password, and won't allow me to go any further unless I've combined the accounts.

Is there any way I can get past this?

Thanks

Matt