For some reason, for me, this script on Ubuntu 11.04 cause Apache on the same machine not to start after reboot.
Any idea why?

The solution I found was to run
 sudo update-rc.d bitcoind defaults 92 8
If you already used the update-rc.d command without the numbers, you can undo it with
 sudo update-rc.d -f bitcoind remove

The 92 and 8 numbers where found by looking for what numbers Apache got for Kill and Start in /etc/rc0.d and /etc/rc2.d (was 91 and 9)