Yes, you have to promote, a BDC, that already has all your user account info, so that none of the access tokens are changed. When you get your new machine ready, install it as a BDC, get it running in the network so that it will get all the user account info, then promote it to PDC. Just plopping a new machine into place, will (as you discovered) not work, because, essentially, it is not the same machine as before, even if you give it the same name, and set all the domain settings up just the same as before. It all comes down to the access tokens not being the same.<br>
Hope that helps.