I accidentally ticked some crazy box somewhere before rebooting my Ubuntu 7.04, it has goofed up my login screen.
After booting, it presents me with the XDMCP login screen. All it lets me do is search for XDMCP computers on the network, and NOTHING else. Clicking cancel returns me back to the same screen.
I don't understand how /etc/gdm/gdm.conf works, so I replaced it with factory-gdm.conf to try that.
I also installed XDM at some point during my fiddling and now I don't know what on earth I'm doing. After screwing about I ended up with the default 'Debian Linux' gui login screen.
Doing that lets me log into gnome/ubuntu but half my thingies dont work. It tells me GDM isn't running.
I replaced the /etc/gdm/gdm.conf with a happy version from a properly running Ubuntu 6.10. It didn't make any different.
After all this I have apt-get remove xdm and am now back to square one.
Whenever I boot, I am presented with a thingie which lets me choose which XDMCP computer I want to log into. Luckily I have my desktop to log into. (A side note - beryl works over XDMCP. Its VERY cool seeing 3D effects and a rotating desktop over a network connection.)
I'm really stumped. I would just like my Ubuntu to go back to logging in with GDM using the standard login prompt. Then I can go back to fiddling with silly ATI stuff with video.