It appears that SCSI disks initialized with HFS or HFS Extended mount fine on a local machine with a SCSI card installed. However, HFS disks cannot be mounted across a local network ... but HFS Extended disks are seen and mounted by OSX and OS9. Hmmmmm.
[robg adds: If anyone can confirm this, I'd appreciate it. I don't have a SCSI drive...]
Mac OS X Hints
http://hints.macworld.com/article.php?story=20030318163354186