Solved my own problem (and hopefully some of yours...). I ended up following the instructions on this page:
http://www.tonymacx86.com/401-install-bootloader-extra-efi-partition.html
Which jogged my memory that I had followed those instructions a while ago to get my latest video card to work. I'm not much of a computer whiz, but my guess is that because I had fiddled with the EFI to get the video card to work it was somehow causing the system to not see the Chimera 4 that I was installing with Multibeast? Who knows. All I know is that those instructions did it for me and my machine is booting on it's own again.