Had same issue with this myself at one point. (went from v1 realease to RC3)
Ensure when you install you use:
diskutil eraseVolume "HFS+" "EFI" /dev/diskXs1
the follow through on the rest of the partition writing commands to install.
This was how *I* fixed it : the above, then went back to RC1, then stepped to RC2 then (after verified boot) switched to RC3.
Also, there have been some reports if you don't put your CHAM drive on SATA0 the bootloader will hiccup
Pax