join sbs 2k3 domain no updates

I'm trying Vista and found that if I check for updates from Vista before I join my SBS 2K3 domain that I have 7 or so. But, I also installed Vista on a few identical clients and joined them to my domain before checking for updates and have noticed that these clients show NO updates available when I check for updates.
Any ideas anyone?
I was able to use one of the machines that did get the updates and produce a list of updates which allowed me to do a manual download on most and install them that way.
Not a single update however after joining the domain and then checking for updates!