This problem is so damn weird and frustrating that I thought it would be worthwhile to post this solution for anyone who may run into this situation in the future, since I was unable to find any mention of this after much searching, and no error messages appear in any logfiles that I could find either.

This applies to a machine with a Atom Processor D4xx/D5xx/N4xx/N5xx Integrated Graphics Controller (according to what lshw tells me).

PROBLEMS FOUND: Live CD: When booting off a a Live CD, the computer boots off of the CD and then loads to the point where the GDM login should show up (and then say "automatic login"), but it stalls at that point and nothing further happens. The blue gdm background screen appears but nothing more.

Net Install CD: When installing from a netinstall CD, the entire installation works perfectly (in graphical mode). After the installation is completed you reboot the machine and the usual firstboot stuff (set timezone, create username, etc) comes up and runs as usual. After finishing the firstboot stuff, you reboot and the machine loads to the GDM background screen. The "enter password" box never appears on the screen.

If you log in to text mode, then type startx, the gnome desktop loads to the point that the blue background screen shows up, and that's it. Nothing further happens until you ctrl-alt-backspace and kill the Xserver.

There are no unusual error messages in any of the log files (/var/log/Xorg.0.log, /var/log/messages or any of the log files under /var/log/gdm), which makes this issue a challenge to run down.

SOLUTION: Running GDM and X on the Atom Processor D4xx/D5xx/N4xx/N5xx Integrated Graphics Controller requires that you create a file in /etc/X11/xorg.conf.d that I named 10-monitor.conf.

Here is 10-monitor.conf:

QUOTE Section "Monitor" Identifier "Monitor0" EndSection

Section "Device" Identifier "Device0" Driver "intel" #Choose the driver used for this monitor EndSection

Section "Screen" Identifier "Screen0" #Collapse Monitor and Device section to Screen section Device "Device0" Monitor "Monitor0" DefaultDepth 16 #Choose the depth (16||24) SubSection "Display" Depth 16 Modes "1920x1080" #Choose the resolution EndSubSection EndSection END OF QUOTE

Change the Modes line to match the resolution of your monitor, of course.

That's it. Problem solved. GDM loads and Gnome works as expected.