I dealt with this issue over a year ago with a big project I worked on. I think this has to do with Windows 2003 applying the policy at boot up. Does your script remove and add the printers when it is applied? Check the links above. I used vb to remove all printers, add new printers, and set default (old printers on network would be removed to prevent problems.)If you need a better example let me know.
I think in this particualr scenario, I created OUs for each office and applied the script to that office for said number of printers.
Hope that helps!