Automatic Update won't start

Hi everyone,

I'm not using WSUS in my domain because I don't have time to set it up so I
decided to schedule AU on every computers on my domain. I tested it on one
computer and it did work fine. The updates has installed correctly and the
user logged on the computer had no choice but to reboot after 5 minutes (like
it's suppose to do). So I've configured AU on more then 40 computers.

Since June 14 (I think...), new updates are available to download and not 1
computer on my network has installed the updates yet. Only 1 computer had the
option in Start --> Shutdown, "Install updates and Shutdown". I decided to
test it again on the same computer I used before to do the testing. I've set
AU to update automatically at 10am this morning, but at 10, nothing happened.
Here's the Windows Update log I get after 10:

2005-06-16 10:00:09-0400 1080 730 AU received event of 1
2005-06-16 10:00:09-0400 1080 730 Forced install timer expired for scheduled
install
2005-06-16 10:00:09-0400 1080 730 Setting AU scheduled install time to
2005-06-17 14:00:00
2005-06-16 10:12:12-0400 1080 43c Service received logon notification
2005-06-16 10:12:12-0400 1080 730 AU received event of 3

The only thing that has changed since my first test is that I installed SP2
on all computers.

If someone have an idea on what's happing, please share your thought because
I think I'll go crazy sooner or later....

thanks!

Martin