Error: Check eMail when Register after guest checkout

Hi,
when my customers click the Linsk in the email for "Registration after Guest checkout" they get a form with these fields:
Name
Username
Password
Password again

After clicking on "Register" the Message "Check your e-Mail Adress" is shown.

Why is this error Message? The eMail Adress should be taken from the guest-purchase, or not?

Thanks for help!