Here's another data point regarding the GDM problem I'm having. Once again, I get this on the console: There was an error loading the theme Default Couldn't recognize the image file format for file '/usr/share/gdm/themes/Default/background.png' Yesterday I needed to edit some graphics I had done for a job. I use gimp. Now gimp tells me: Image type 'png' is not supported Soooo ... the problem appears to be with png support and not with GDM at all. Jim asked me to run "rpm -Vv gdm" which produced: [snip] prelink: /usr/bin/gdmXnestchooser: at least one of file's dependencies has changed since prelinking S.?..... /usr/bin/gdmXnestchooser prelink: /usr/bin/gdmchooser: at least one of file's dependencies has changed since prelinking S.?..... /usr/bin/gdmchooser prelink: /usr/bin/gdmflexiserver: at least one of file's dependencies has changed since prelinking S.?..... /usr/bin/gdmflexiserver prelink: /usr/bin/gdmgreeter: at least one of file's dependencies has changed since prelinking S.?..... /usr/bin/gdmgreeter prelink: /usr/bin/gdmlogin: at least one of file's dependencies has changed since prelinking S.?..... /usr/bin/gdmlogin prelink: /usr/bin/gdmphotosetup: at least one of file's dependencies has changed since prelinking S.?..... /usr/bin/gdmphotosetup [snip] prelink: /usr/sbin/gdmsetup: at least one of file's dependencies has changed since prelinking S.?..... /usr/sbin/gdmsetup [snip] This also points to something else. What that is I don't know. I don't change system stuff. Jack