If you've got a domain going, why aren't you mapping the printer with a login script? AFAIK that's the standard way to do it. It Works Just Fine here at work. I can find the login script for you if you'd like, but it's essentially "net use \\pathto\printer".
(I thought that's what one of those MSKB articles I linked above says to do, but now I see it's more complicated than that). I think it sucks that you'd have to do that at all, but whatever. By the way, I think that the NET USE command is only part of the equation, that allows you to use the printer but doesn't necessarily install the driver and set it to be the default printer. That's what the printUI.dll command is for. (if I'm understanding correctly.)