Some additional info: I have to be logged in with my own account locally. If another user is logged in locally me remote login fails in same way.
I put enable=true into [debug] section of gdm.conf. Now I have a big log-file and I can see the differences at the entries in /var/log/syslog. But I am a programmer working on Windows and small embedded systems and my knowledge about about X- and GDM- startup is not good enough for this task. For me it looks a little bit like access-right problems, but I don't have a real clue and don't know how to debug this. -- GDM sometimes does not start correct on XDMCP remote session https://launchpad.net/bugs/62031 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs