Well, I forgot my redmine.org username and hit "Sent Password Reminder" - but as I still knew my password - this reset password and set new procedure was quite useless to me ;-) I still lacked the username....
What about accepting the registered email address as login also? Or sent the username with the password reminder email.
By the way once entered the "username" is no longer visible, is it?
I finally found the username by trial and error ;-) I am so stupid ;-)