Some time back I was lamenting that IP over Firewire didn't seem to be working in Leopard. I routinely use IP over firewire in the data center to have out-of-band communications (backup, heartbeat etc) between servers. With an early version of Leopard (10.5 or 10.5.1) it wasn't working at all. Today I was getting back to checking for possible work-arounds. Fortunately before digging in too far I decided to try it and low and behold it works just like it used to.