So you say you can boot from IDE and write to SCSI, but if you read from SCSI you get errors?
Which error message? Please quote it exactly.
When you boot from SCSI, do you disconnect the IDE drive or how do you choose the boot drive?
What if you boot from IDE and then copy all files from the IDE boot partition to the SCSI boot partition without installation and then boot from SCSI?
Does it boot from SCSI when the IDE drive is connected?
Can you boot from SCSI without startup-sequence and then
set echo on
At which point does the error message appear? Does it always appear at the same point?
What happens if you boot from IDE and then copy all files from the SCSI drive to RAM:?