Comment 6 for bug 228406

For the record, this happens on ALL upgrades, and is a result of us having moved the procps.sh start link from S30 (debian's default) to S17. The postinst attempts to remove S30procps.sh (as well as S05procps.sh, for historical reasons) on upgrade, which fails for Ubuntu:

       # Remove old procps init.d script, if it exists Closes: #55137
       if [ -L /etc/rcS.d/S30procps.sh ]
       then
          update-rc.d -f procps.sh remove >/dev/null
       fi
       # and if that didn't work Closes: #92184 (#234306 with -L )
       if [ -L /etc/rcS.d/S30procps.sh ]
       then
           rm -f /etc/rcS.d/S30procps.sh
       fi
       if [ -L /etc/rcS.d/S05procps.sh ]; then
           rm -f /etc/rcS.d/S05procps.sh
       fi

If one were to add S17procps.sh to this code block as well, it would solve the problem nicely for Ubuntu upgrades.