In the gdm.conf server-standard, I have this line in there since before I posted any of the nvidia-bug-report.log files in this thread:
command=/usr/bin/X -br -audit 0 -logverbose 10
All the arguments except the logverbose were in there before I edited that file.
Where I've printed out excerpts from Xorg.0.log, that is my effort to determine why 720x480 is not being used by the X server.
Not sure if you're aware, but the nvidia-bug-report.log includes the full contents of Xorg.0.log and xorg.conf.