I will try to setup GPT boot on my Macbook and see if I can boot Haiku that way, if not then I think I need to skip REfit. I tried it in the past and it wasn't for me.
UPDATE: I Setup GPT on using the Disk Utility by Formatting the Drive as MS-DOS and choosing GPT in the options. Apparently, the Haiku Installer calls it a FAT32 EFI partition. I installed Haiku on the 2nd Partition, leaving the first intact and I get the same issue, where I can't boot an OS. Too bad.