Based on suggestions in the OSX Help forum, I've now used this 3 times on 2 computers (running 10.2.x. and 10.3.3 to solve printing problems, so I think it deserves Tip status.

Problem: Can't print, although printer is visible in Print dialog. Attempts to add and/or reinstall printers might or might not be possible. Typical (for me) is that the "searching for new drivers" process either ends unsuccessfully or has to be force quit.

Solution: Create a new user in the Accounts section of System Prefs. Login as that user and add your printers. Logout and return to your main identity and the printers should now function.