I hate to post this, but be sure, I have spent hours with Google without success.
I have been using parallel X-Sessions (CTRL+ALT+F7,F8,..) for a long time now. I am aware, that default xdm rpm, has only one entry in Xservers file. I think this is something that should be changed, because I have to change it after each update. Anyway, that is not my problem.
Everything seems to be set up right. In KDE menu, I see the item to start the new session and I can click on it. On my account i have disabled the message window explaining what happens, so nothing happens when I click on the menu item.
Using another user, I get this message window, but no new session.
I have found no error messages in the log files I checked. When I start X from command line, it starts on :1 too, no problem.
As long as I searched I have not found a good or at least usefull documentation how it really works. So I am completely stuck.
Please help! Thanks!