After moving a Lite-on CD/RW drive to a FireWire enclosure, I found I had trouble getting it to be recognized by both my Macs and my XP machine. After a long search, I came across this report on xlr8yourmac.com. Basically, you have to Modify the firmware to report drives with non-standard sigs (a checkbox available from the Advanced options in the Modify Configuration Information section).
But after finding the latest firmware uploader, I found it had been restricted. The latest unrestricted version is available from Triumph's support page.
Mac OS X Hints
http://hints.macworld.com/article.php?story=20040104054132790