I typically don’t make “hacks” to my system, but I just tried the Netputing’s AirPrint Hacktivator and it clearly works…  And works quite simply.
Run the tool, turn on AirPort Printing, and then delete and re-add your printer (so that the changes are seen).
HOW TO Hacktivate:
1. Launch AirPrintHacktivator
2. Click on the togle switch:
3. Enter the admin password:
4. A window will appear instructing you to remove/add/share the printer you want to use with AirPrint:
Click OK.
5. The Print & Fax System Preference window will open to allow you to perform the remove/add/share task.
That’s it! Â Simple, and it works…