Good question, and yes, udev DOES keep track.
check in /etc/udev/rules.d for file names with *persistant* in them. There are several, and one for -- you guessed it -- network/NIC data.
By removing the persistent file(s), udev will rebuild it with the correct/current info.
This is how you install on one platform and put that disk into another.: Remove the udev persistant rules in the post-install.
Phil, This is exactly what I did, I moved the file out altogether. Should I have simply removed the line in it? It recreated the file next boot with the old mac address only to still cause issues!
Thanks, jlc