First is that you cannot use the embeded web server functions through a USB connection, which is what you have configured.
Second, isn't this a wireless enabled printer? If so you should be able to connect to it wirelessly without directly connecting it to the AE. You should set it up to agree with the LAN created by the AE, for example, setting it to recieve an IP address fromt the AE.
I recently purchased an Airport Extreme to replace my router. The Airport Extreme does a good job connecting to the Internet, but I have problems with my Airport Extreme when it comes to printing. I followed the troubleshoot guide for Airport Extreme dealing with printing issues, but apparently it does not work. When my printer (HP Officejet J6480 All-in-One) is connected to my Airport Extreme via the USB, my Airport Extreme can read and display in the printer section of the AE utility software. I have downloaded Bonjour for Windows from Apple and installed the Bonjour Printing Wizard and successfully installed the printer to my computer. However, whenever I print, the information is not sent to my printer because whenever I check "what is printing" there are no pages printing. I do not understand why I cannot print from Airport Extreme. I hope I can fix the problem.