Root file system not showing in df or mount in Edgy

HI,

I upgraded to Edgy a few days back and after a few "teething problems" thought I was OK - however I've just noticed that the root file system does not show up in df or mount

dom@tiny:~$ df -h
Filesystem Size Used Avail Use% Mounted on
varrun 1014M 120K 1014M 1% /var/run
varlock 1014M 4.0K 1014M 1% /var/lock
procbususb 10M 156K 9.9M 2% /proc/bus/usb
udev 10M 156K 9.9M 2% /dev
devshm 1014M 0 1014M 0% /dev/shm
lrm 1014M 18M 996M 2% /lib/modules/2.6.17-10-386/volatile
/dev/hdb1 97G 97G 0 100% /mnt/backups
/dev/hdb2 88G 66G 18G 80% /var/lib/vmware
dom@tiny:~$
dom@tiny:~$ mount
proc on /proc type proc (rw,noexec,nosuid,nodev)
/sys on /sys type sysfs (rw,noexec,nosuid,nodev)
varrun on /var/run type tmpfs (rw,noexec,nosuid,nodev,mode=0755)
varlock on /var/lock type tmpfs (rw,noexec,nosuid,nodev,mode=1777)
procbususb on /proc/bus/usb type usbfs (rw)
udev on /dev type tmpfs (rw,mode=0755)
devshm on /dev/shm type tmpfs (rw)
devpts on /dev/pts type devpts (rw,gid=5,mode=620)
lrm on /lib/modules/2.6.17-10-386/volatile type tmpfs (rw)
/dev/hdb1 on /mnt/backups type ext3 (ro,errors=remount-ro)
/dev/hdb2 on /var/lib/vmware type ext3 (rw,errors=remount-ro)
nfsd on /proc/fs/nfsd type nfsd (rw)
binfmt_misc on /proc/sys/fs/binfmt_misc type binfmt_misc (rw)
dom@tiny:~$

It is in /etc/fstab and the UUID from vol_id checks out with /etc/fstab. However if I look at /etc/mtab there is no entry for /.

dom@tiny:~$ cat /etc/fstab
# /etc/fstab: static file system information.
#
# <file system> <mount point> <type> <options> <dump> <pass>
proc /proc proc defaults 0 0
# /dev/hda1 -- converted during upgrade to edgy
UUID=a3de38df-11f4-4598-bb06-adc801711814 / ext3 defaults,errors=remount-ro 0 1
# /dev/hdb1 -- converted during upgrade to edgy
UUID=ade8e598-2183-4f31-a095-d9130a4950db /mnt/backups ext3 ro,defaults,errors=remount-ro 0 1
# /dev/hdb2 -- converted during upgrade to edgy
UUID=2f3a65a1-88b1-44f2-b5c4-ce00173b406a /var/lib/vmware ext3 defaults,errors=remount-ro 0 1
# /dev/hda5 -- converted during upgrade to edgy
UUID=72e6342f-3bc4-4350-9f09-b2fac1aac84d none swap sw 0 0
/dev/hdd /media/cdrom0 udf,iso9660 user,noauto 0 0
/dev/hdc /media/cdrom1 udf,iso9660 user,noauto 0 0
/dev/fd0 /media/floppy0 auto rw,user,noauto 0 0
dom@tiny:~$ cat /etc/mtab
proc /proc proc rw,noexec,nosuid,nodev 0 0
/sys /sys sysfs rw,noexec,nosuid,nodev 0 0
varrun /var/run tmpfs rw,noexec,nosuid,nodev,mode=0755 0 0
varlock /var/lock tmpfs rw,noexec,nosuid,nodev,mode=1777 0 0
procbususb /proc/bus/usb usbfs rw 0 0
udev /dev tmpfs rw,mode=0755 0 0
devshm /dev/shm tmpfs rw 0 0
devpts /dev/pts devpts rw,gid=5,mode=620 0 0
lrm /lib/modules/2.6.17-10-386/volatile tmpfs rw 0 0
/dev/hdb1 /mnt/backups ext3 ro,errors=remount-ro 0 0
/dev/hdb2 /var/lib/vmware ext3 rw,errors=remount-ro 0 0
nfsd /proc/fs/nfsd nfsd rw 0 0
binfmt_misc /proc/sys/fs/binfmt_misc binfmt_misc rw 0 0
dom@tiny:~$

Running sudo mount -av gives me:
Code:

mount: proc already mounted on /proc mount: UUID=ade8e598-2183-4f31-a095-d9130a4950db already mounted on /mnt/backups mount: UUID=2f3a65a1-88b1-44f2-b5c4-ce00173b406a already mounted on /var/lib/vmware

Watching the boot carefully I see what appears to be the mount help displayed as if mount has been run with an invalid argument but I am unable to find this in a log file anywhere to check.

Probably unrelated but I am booting with the irqpoll option.

Any suggestions on how to troubleshoot this would be appreciated!

Dom