CentOS 6.5 - ELRepo kmod-nvidia - X fails to start on boot

I have a CentOS 6.5 box with a GT610 in it. I’ve installed kmod-nvidia and the nvidia-x11-drv RPMs. On boot, whether I have runlevel 5 in /etc/inittab or runlevel 3 and try startx, X will not start. What’s strange is that I get no /var/log/Xorg.0.log with runlevel 5 in /etc/inittab. However, in either case, if I ssh in and init 3 init 5, I get a fully functional desktop, GLX and all. If I startx in runlevel 3, CTRL+C, and startx again, it works. I can’t get any combinations to work on boot though.

Thanks for all your help, here’s my nvidia-bug-report.log after a failed startx --logverbose 6 in runlevel 3.

EDIT: Also. If booting into runlevel 3, I can ssh in and init 5 (without an init 3 first) and get a working desktop.
EDIT2: After a failed boot with inittab set to 5, /etc/X11/prefdm -nodaemon boots me into a working desktop. I see no messages about prefdm in /var/log/messages. Where does prefdm normally get called? I can’t find it grepping through /etc/rc.d or /etc/init
nvidia-bug-report.log.gz (66.8 KB)

Small update: As part of a recommendation on the CentOS forums, I removed the xorg-x11-glamor package. This did not change the issue as I had already removed glamor.conf from /usr/share/X11/xorg.conf.d.

Another update. After another failed attempt at booting into runlevel 5, I tried my /etc/X11/prefdm -nodaemon. Both as root and as standard user, neither work.