Until today, I was having a problem that sounds in some ways similar to those discussed in this threat.
I have an HP Laserjet 1220 connected by USB cable to a second generation Airport Extreme. Under OS X 10.5 I was able to print to the Laserjet fine over my Airport Extreme WiFi network. When I bought a new MacBook Pro running Mavericks, I wasn't. I also noticed that the Airport Utility 6.3.2 could not "see" my Airport Extreme - although I did have internet connectivity. I have spent around six hours on the phone with various Apple experts (and HP experts), having logged official support cases with both, and these calls have included several screen-sharing sessions, trying to solve this problem - without success. Along the way, I tried several times turning off my Mavericks firewall, but that had no effect.
Today, however, I noticed in my Firewall settings that with the Firewall ON (which is normally is) incoming connections were disallowed for mDNSResponder. As soon as I changed this setting to allow incoming connections, the Airport utility was able to see my Airport Extreme, and I was able to create a printer for my HP Laserjet 1220 and print to it.
I'm not saying this will be the solution to everyone's problems, but it has been the solution to mine.