Software Update can’t connect to the update server. Make sure you’re connected to the Internet, and then try again

I have been getting this message on MAC OS 10.6.3 "Software Update can’t connect to the update server. Make sure you’re connected to the Internet, and then try again". Internet is working fine for everything else. Updating to 10.6.8 and applying all the security updates and patches [directly downloading from the apple website] has not resolved the issue. Read somewhere about a software update enabler for 10.6, installed it, but not helping.. [not sure of the update server settings to be entered] .Is there no way to make the software update work from the Apple Start Menu??