Comment 6 for bug 63418

Ok one more thought before I believe this bug stays unnoticed.

The lockup occurs in different points of bootup, but always during or after an fsck. This agrees with your observation Dr D J Clark.

During: Usually during a forced fs check
After: Meaning the next checkpoint for bootup is already being displayed, but then the lockup occurs

The asynchronous behavior makes me guess it has something to do with upstart.
upstart was last updated on Mi, Okt 11 2006 00:05:09 +0200, which is in the range when I think the lockup probability changed.

fsck or something like e2fs* was never updated since start of the logfile.