I'm not sure if this will work in Harmattan, but in Fremantle, you could put a script in /etc/event.d and it would run at boot:
http://wiki.maemo.org/Startup_script

Did you install Inception? If so, is it posiible to stop it from starting at boot up? The following thread explores the boot process in Fremantle, so there may well be similarities with Haramattan:
http://talk.maemo.org/showthread.php?t=87959


Also, it would be helpful to others who may have the same issues as you in the future if you could document what has worked so far for you.