In regards to running K-STAR 9.1.2 on a Fastpath 4. Reading old USENet posts, its very apparent that I'm not the only one that had problems with the unit crashing with 4.x PROMs. You should be able to safely run 9.1.2 with the 5.1 PROMs whenever you get them.

Somewhat unrelated, but out of the 3(!) Fastpath 5s currently in my possession, each one is different inside.

#1 has a green PCB and 5.0 Boot PROMs.

#2 has a green PCB and 5.1 Boot PROMS.

#3 has a beige PCB and 5.1.1 Boot PROMs.

All of them say its a Rev. A PCB. Now I just have to track down the official manuals for the Fastpath 5 so I can scan them....