Install rcconf if you don’t have it yet. rcconf is Debian’s runlevel configuration tool. It allows you to enable or disable the services from starting up automatically. Recently, I got annoyed by postgresql starting up at boot time, so this tool did the trick.
Source: http://www.cyberciti.biz/faq/howto-runlevel-configuration-tool-to-start-service/
ah that is a nice one.