So... I haven't gotten to a successful installation yet, but I think I
figured out what the problem was.

I had a 3ware 9650se driving a 4x750 raid5.  What I forgot to was
carve (I think this is the term) a boot volume out of the main array.
That is, now I've got one 50GB drive, and one 2045GB drive, but they
have the same constituent drives.

PC's (as far as I know) can't boot off of a block device that holds
more than XGB, where X is > 50 but less than 2045.  Many RAID cards
allow you to create a smaller boot parition (which looks like a
seperate scsi disk to the OS) but is part of the main array.

Like I said, I haven't finished, because I'm in the process of
rebuilding the array.  But I'll bet thats what the problem was.

"Come on guys... Its all ball bearings these days."