OEM XP Pro COA Activation Problem

The last two OEM copies of XP Pro that I have purchased and installed on new
customer PCs have exibited a strange problem. Upon initial startup you are
prompted to enter the Admin password and then Activate Windows. This would
be OK except the LAN drivers have not been installed yet. So it fails and
does a Shutdown.

I determined this behavior is tied to the Product Key as an older
(activated) key will start normally but of course not activate. I use the
procedure outlined in KB328874 to change the key to the new one then
Activate. This is a major PITA!

What is causing this? This has now occurred on OEM copies from two major
suppliers that claim the product is legit (looks OK to me).

Any suggestions would be appreciated!