Allow me to quote and additionally repeat my last mail.

> From: John Nemeth <jnemeth@cue.bc.ca>
> first thought is correct, it is a geometry problem.  sysinst wants to
> use the "real" geometry, but it must use the BIOS geometry for the
> disk to be bootable. 

NEVER NEVER NEVER, use the true disk geometry for an adaptec scsi disk.
The heads/sectors are either 64/32 (for disk < 1G) or 255/63 (for disks
> 1G)

PS
In the sysinst I have tried, you are given the choice of bios labels
or real geometry.