Unable to authorize book using Feedbooks Vendor ID

An EPUB file was previously authorized using an Aldiko-Feedbooks DRM account. When I try to open it in ADE i get a message stating that it needs to be authorized using a Vendor ID. ADE then asks for the Vendor ID and password. When  I enter this info, as used on the Feedbooks.com website, I get this message:

Can somebody help? Is this a login/password problem? Or is ADE using outdated links to the vendor?

Thanks in advance.

/Ulf