I was making the changes to nasCommon.pm as suggested in order to continue being able to use the GUI whilst keeping Samba running off ramdisk. By the time I'd finished reading it and making my changes the drives had spun-down.
On writing the file using :wq in VI, the file saved and is now 0 bytes long. Totally empty.
Would somebody mind posting the original nasCommon.pm script as I'm scared to reboot or power off the MyBook in case it doesn't come back up again. I'm on 2.00.15 firmware.