I got my Tiger upgrade today. My upgrade experience is detailed here, but that was the least of my trouble.
My LCD display, which I’m using with my Linux box, died. This is the first time I’ve had one die, but it is my oldest LCD display. Luckily I still have my old CRT, which flickers very badly. Before I swapped monitors I shut down the linux box. It’s been running for 77 days without a reboot until now. When I rebooted it, I found that none of my Macs could mount the nfs share. In fact none of my other machines could see it, although it could see everything else. I realized that Firestarter was enabled at startup and the settings were too restrictive, blocking all incoming connections. Once I fixed it, everything worked again.