Just tried a fresh install and multibeast 5.0.2 fails to install. I wish there was a way to recover from that with reinstalling!
[COLOR=#000000]sudo kextcache -system-caches[/COLOR]
[COLOR=#000000]sudo kextcache -update-volume /
Try booting with GraphicsEnabler=No ... may have over written your settings.
What monitor are you using and are you using DVI or HDMI to connect to it?