HP OfficeJet 5110 and Airport Extreme Printing
HP indicates they do not support use of all-in-one devices when connected via Airport. Despite this, some of these devices will still work - but if it doesn't, one shouldn't be too surprised.
The workaround requires use of the third-party printer drivers designed for the OS X CUPS printing system. First, download and install the Gimp-Print driver for a DeskJet 900 series printer (compatible with the OfficeJet 5110). Then run the Printer Setup Utility, and Add a new printer using "IP Printing" and the "socket/JetDirect" printer type to the IP address of your Airport - usually 10.0.1.1. Then select the Gimp-Print DeskJet 900 series driver you just installed.
Note this HP Page if you have a HP PhotoSmart or All-in-One printer.