As far as I can see, the somewhere in the init process the mtab-entry is created by a call to mount -f / which does not mount, but write the mtab entry. In this process, data is fetched from /etc/fstab. This is sensible for all fstab-entries, as these are used for regular mounts as well. But for the root file system this can lead to the paradox situation that fstab points to a device that is not mounted as root, without producing errors (but leading to wrong information).
Patrick -- Engineers motto: cheap, good, fast: choose any two Patrick Strasser <patrick dot strasser at tugraz dot at> Student of Telematik, Techn. University Graz, Austria -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]