Version: (using KDE 4.2.2) Installed from: SuSE RPMs The login manager under the advanced tab in the personal settings offers the auto login feature. Activating it and applying it does not show any error, yet the feature does not work. Actually the settings is never saved to kdmrc, though no error is generated. Certainly this might be limited to the suse rpms, cause the yast2 tool offers auto login too, whith the setting being stored under /etc/sysconfig/...
Update after 2.5 years of being an open bug. Currently using KDE-4.7.4 the issue looks like this: The feature can be enabled as before. It is actually saved and restored next time you access the login manager. However the setting has absolutely no effect. Many people state that the auto login feature is insecure. That may be the case, but that is another question. In my eyes we are talking about a feature here that is offered but does not work. This is a bug. Either the issue should be fixed or the feature shoould be removed.
not sure what the original problem was - possibly something distribution specific. the current problem ... well, the same. possibly a pam setup problem, some random messing with kdmrc (debian does that), or whatever else. the feature itself works and didn't change much in a decade. please seek support in an appropriate user forum.