Changing the user of transmission

I have transmission installed as per this guide

http://forum.xbmc.org/showthread.php?tid=61574

But i had to set it to download to /home/xbmc/Downloads as the user is set to debian-transmission by default.

I edited the daemon to try and run it as xbmc

sudo nano /etc/init.d/transmission-daemon

by changing the line

USER=debian-transmission

to

USER=xbmc


But then it refused to start. How do i get it to run as xbmc instead of debian-transmission ?