I do not have a solution to your problem but I would suggest to point a browser to 127.0.0.1:631 and configure CUPS from that. You will inteact directly with CUPS and it is better for debugging. Now can you see your printer from there?
I have Fedora 17, KDE. I open Printer Configuration and choose New Printer. I a CUPS server error, "There was an error during the CUPS operation: ' cups-authorization-canceled'. The printer is plugged in.
I previously added a Photosmart-C2400 sucessfully.