Problem adding hard drive to dual boot

I am trying to add a third hard drive to a system that dual boots win98 and 2kpro. 98 boots off of the 60gb IDE drive (full specs bellow) which is the master on IDE 1. 2000 boots off of a 37gb WD Raptor. Everything is cool until I try to add the 250gb IDE drive on the as a slave to the 60gb drive.

The error message I get when trying to boot 2000 is ".....couldn't start because the following file is missing or corrupt: <windows 2000 root>\system32\ntoskrnl.exe.

The error message leads me to believe that bios is looking at the 250gb hard drive to find windows system files and not finding them. I've tried swithing the boot order in bios so that HDD 0 (the 60gb win98 disk) is first and SCSI (the win2k raptor) is second. I also tried disabling other boot devices and various other permutations, to no avail. Is it not possible to have the 250gb NTFS storage disk on the same IDE as the FAT32 disk?

I've run out of ideas. Finally, system specs:

mobo: Abit NF7-S
OS: win 98 SE and Win 2kPro
hard drives: a) Seagate barracuda IV 60gb 7200rpm IDE
b) Western Digital Raptor 37gb SATA
c) Western Digital Caviar 250gb IDE