Comment 13 for bug 134503

I uploaded a new cupsys which *might* be the cause of this. If it was, it would be very dubious how it happens, but it is a safe change anyway.

cupsys (1.3.2-1ubuntu7) gutsy; urgency=low

  * debian/cupsys.postinst: Drop ancient transitional code to remove root from
    group lpadmin. Under very odd circumstances ("root" has the same UID than
    the user) this could cause the user to be removed from group 'lpadmin'.
    Quite unlikely that this is the prime reason for LP #134503, but it's much
    cleaner in any case.

 -- Martin Pitt <email address hidden> Mon, 15 Oct 2007 12:32:16 +0200

Can you reproduce this from a clean Feisty installation?