Does your copy include the debian headers, as given by mgillespie in: http://www.plugcomputer.org/plugforum/index.php?topic=485.0#msg5425Mind you, on looking at that more closely it appears to be wrong. The
Required-Start; checkfspart means that it will run after checkfs, but I suspect you need it to run before checkfs.
To do that you can leave the
Required-Start:in wait4usbdisks empty, (i.e. you'll need to edit it to remove the checkfs that is there) but add wait4usbdisks to that line in the checkfs.sh script (after checkroot - with a space in between them).
update-rc.d wait4usbdisks defaults