ext4 fs going backwards in time

[Jesper Fruergaard Andersen]

I have a desktop running ubuntu 9.10 with the root fs being ext4 on
raid1. The desktop has an additional ext3 fs also on raid1.

I tried to upgrade it to 10.04 using do-release-upgrade which seemed
to work fine. But when I rebooted it failed complaining that /dev/shm
was missing.
I then rebooted on a 10.04 install cd and accessed then filesystems.
The additional ext3 fs seems fine but the strange thing is the ext4
root fs. fsck runs without any complaints. But the content seems to
have stepped about 2 month back in time.

/etc/lsb-release shows 9.10
Content of /home have recent files missing and the newest timestamp is
about 2 month old.

How can a filesystem loose about 2 months of updates and return to
what appears to be an old consistent state?
Anything I can do to return to current time.

-- 
Jesper