I think you MIGHT both just have the problem that your machines are not upgraded far enough. Best thing to do might be to just open up your Software Update and go wild.
I remember back in 10.0 esp. there was a slight problem with Software Update and it would regularly not show the next updates.
Remember that when you get the installer update for Software Update you then have to close off the system preferences and reopen them and check for updates again. There are WAY more updates after you do the installer.
Forget about stuff like Airport at first, just do the system and security updates. If it still does not work, do the other updates and see if there is another installer update that it has been holding back on.
Sorry, this is my best advise for the moment.