Superfluous fstab Entries After Upgrading to Lucid LTS

A quick post to outline a stupefying problem I encountered after upgrading one of my machines to Ubuntu Lucid (10.04) this weekend. By way of background, I am anything but an early-adopter of OS releases — especially on my production hardware. I haven’t the time to debug network-critical software on systems on which I rely heavily, so I typically lag a major-version-release or so behind the “cutting edge”.
Yesterday I finally made the move to upgrade to Lucid LTS on one of my servers on my home network. The automatic upgrade apps downloaded and executed without a hitch, so I was optimistic upon reboot. For reasons which surpass understanding, however, I received an error indicating that the hard disk upon which I had installed the OS refused to mount at boot time — although, to Lucid’s credit, I was given an option to skip this mounting and continue with the boot.
The whole episode was absurd, as the disk was clearly mounted and booting — how else was the OS loading at all if the disk upon which it resides would not boot? Upon logging in, a quick cat /var/log/boot.log suggested that there was, indeed, an error in mounting /dev/sda1. cat /etc/fstab made clear what the problem was — somehow there were additional entries in the fstab file which tried to mount the partitions on /dev/sda subsequent to their initial mounting. I’ve not the slightest idea how these entries made their way into the file. I am, however, confident that they were not there prior to the upgrade as this error was entirely new. A few keystrokes in vim and I had commented-out the offending entries. Upon reboot, all was well with the server.
Most perplexing …