Comment 6 for bug 884402

You can fix it on ubuntu oneiric (11.10) by editing the file
/var/lib/dpkg/info/libapache2-mod-shib2.postinst

and on line 45:

replace:
update-rc.d shibd start 20 2 3 4 5 . stop 20 . >/dev/null

with:
update-rc.d shibd start 20 2 3 4 5 . stop 20 0 1 6 . >/dev/null

save file and you're done, install the package again.
you will get a warning about non matching LSB stop headers that you can safely ignore.

Note: you must attempt to install this package the first time and fail before you're able to use this workaround.

Hope this helps