Sometimes other Microsoft programs are "tied in" to Windows Updates. Are you running Security Essentials or any other Microsoft programs? Even Microsoft Office could possibly affect that as well.
It's possible but there's probably another culprit. What other type of security software (non-microsoft and microsoft) if any, is installed on your pc? Also, when you say that you have automatic updates turned off, exactly which option did you choose? The only one that eliminates everything is the option that says "never check for updates"
I strongly recommend against doing this, but you could go to the control panel>administrative tools>services>Windows updates. Double click , then stop the service and change startup type to manual or disable. Again, I strongly recommend against disabling it, but see what happens if you put it in manual first. One other question, are you logged in as an administrator account?