I remastered Knoppix 5.0.1. I upgraded some packages and ripped out most of unnecessary stuff.

Now on some PC's my remastered version just hangs on shutdown/reboot with message:
Code:
unmounting file systems: /UNIONFS/lib/init/rw
To get over this message, hard reboot/power-down is required. On other systems everything works fine (PIII, P4). I have observed such fail on P4 and Core Duo systems, no info about chipsets (yet), also no info about AMD based systems.

Any ideas in to which direction to digg? Hints?