I'm not sure if the pismo had this issue, but I remember that certain Macs and Powerbooks require the OS X partition to be on the first 8GB of the hard drive, otherwise it wouldn't be bootable.

I only have a Wallstreet II so I wouldn't be able to test it, but you could try re-partitioning your drive with the OS X partition being in the first 8 GB (Try 7.8GB to insure that it boots), otherwise I wouldn't know.