using auto update to download sp2

i have been trying to get auto update to work to download sp2 for the past
two weeks. i just recently downloaded sp1 updates and now have the windows
update icon in my taskbar tray. i set auto update to begin at a designated
time but nothing happens. i have turned off my spyware protection and
firewalls and still nothing. can sp2 be downloaded with auto update? do i
have to initialize the download somehow? i also followed the link that lets
microsoft turn on auto update for me, but still no sign of it activating. i
have a seperate firewall program and if i leave it on at the auto update
time, it should detect auto update trying to access the internet. no sign of
it even trying. any ideas as to what is going wrong?
thanx-
k.