Booting RTP with Adaptec 2940 SCSI Controller

I have an extra 2 Gig SCSI hard drive that I threw onto the end of
my current SCSI chain. The controller is a PCI Adaptec 2940. I
downloaded and burned the most recent version of RTP (which supports
booting from SCSI disks) and installed. The installation went
flawlessly. It saw the disk, and had no problems installing to it. My
only problem is that it won’t boot from that disk. If I use grub or LILO
to chainload that partition, it starts loading the kernel (the … start)
but stops after three or four periods with ?80

I can boot fine off a boot floppy, but that’s obviously not an idea
situation. Any ideas what I can do?