If you have KDE installed, try
root># kprinter
and install the printer through that GUI. It works well and it uses CUPS as the backend if needed.
Edit** - just noticed you are using Gnome, no big deal. Try kprinter any way. Also, if you want to access Swat or CUPS through the Browser, you need to uncomment those ports (901 and 631) in a configuration file in /etc/ (i know it's bad, but i can't remember right now what file it was - it's been a while). Also try
http://127.0.0.1:631
When "localhost" wouldn't work, 127.0... would work for me.