10.6.4 Update not being seen as needed on any of my instadmg images.

I have 2 machines that were installed from DVD they both saw the need for 10.6.4 but the rest of the machines i have built via instadmg images do not see the need for 10.6.4. they are all at 10.6.3, instadmg was ran on a 10.6.3 workstation, all other updates have been seen and applied via software update. a proxy is not getting in the way, guessing that the pkg database is confused, but what do I look for?