Took a while to figure out what was causing the hangups. I installed Mac OS 9.0.4 in SheepShaver v2.5 under Linux. Everything went well until I tried to make a remote volume appear automatically after a system boot. That results in a hard hang during boot. Only the clock appears in the menubar and it never progresses past that point. 100% repeatable. If I do not check the boxes in Chooser everything is fine and I'm able to mount manually. Is it possible that networking is not appearing early enough in the boot process?