lost gdm screen

[Trey Sizemore]

Or to be more precise, after an upgrade of gdm, when I log in I get an
error message that the config file contains an error (or unrecognized
command) and that it will use the default.

I'm then presented with the default gdm login screen rather than the
'more stylish' version I had previously.

What changed that the previous gdm.conf file is no longer valid?  How do
I get the 'nice' gdm screen back?

Thanks.