Cannot change user login in users-admin

Thank you for this report. I can confirm this.
However, it's not a bug, but a feature request. Changing the username requires a lot of work. For example $HOME needs to be changed, but also /etc/passwd, /etc/shadow and /etc/groups
And of course you could have some programs assigning certain rights to a user, but using the username for that.
Anyway, I'll forward it to GNOME Bugzilla.

It seems to be introduced in revision 4018 of gnome-system-tools:
http://svn.gnome.org/viewvc/gnome-system-tools?view=revision&revision=4018
        * user-settings.c (user_settings_dialog_new)
        (user_settings_dialog_get_data): disallow changing login name.
        * group-settings.c (group_settings_dialog_new)
        (group_settings_dialog_get_data): ditto for group name.

I'm going to mail the responsible developer to ask why it was changed this way.

Thanks for the replies.
To clarify the subject: I do not want to change the username as in $home. Just want to change the login name to the session.
For example: under Gutsy, I originally had username "marcelo" with login name "marcelo". My home directory is /home/marcelo.
To enter gnome in gdm I had to use login name "marcelo". For practical reasons, I had to change my login name to "mespinoz" which is the login name I have in my other computer in the office. So I went to System->Admin.> Users and groups, and change the login to "mespinoz", buit the home directory is still /home/marcelo and the group is "marcelo" and so on.
I wanted to do the same in Hardy, and I can not do it.
I simply want to change the login name to the session, not the home directory or the group. Under Gutsy it went very easy.

I am interested in this as well, and having seen no activity, am worried that nothing has/will change....Could I possibly get an update?

Thanks!

I think we could add this option to the new Advanced Settings dialog, but we won't move home dir and other things: just rename the user in /etc/passwd. Not sure our architecture allows for this easily.

Hmm, I've checked how this could be implemented, and I'm sorry to say you that would be very hard. Currently, we are identifying users with their login, which means anything can change but that setting. Else we wouldn't be able to find what user it corresponds to.

I'm not sure there are very common use cases for this anyway. Since that would require a special method that would break the general model in the System Tools Backends, I don't think that will happen.