Trying to share a printer between 2 Linux machines

[norm.h]

Two machines, each running Ubuntu 10.10.
Desktop is wired to the router, and laptop is wireless.
Printer is an HP Photosmart C4400 All in One series, and is connected to the desktop via USB.Prints OK from desktop.
I have CUPS set up on both machines, and the laptop can see the printer.
Desktop firewall allows CUPS in on port 631.
Printer properties are set to enabled and shared
Desktop is set to publish printers, and laptop is set to show printers from other systems.
Fine until I try to print from laptop, when print job is shown as sent, but printer remains idle.
Another thing is that on the laptop, the "enabled" setting drops off.
I think this must be a configuration issue, but cannot find an answer anywhere.
File sharing using Nautilus works fine.

[wimstock]

I have a simular setup, the HP office jet is pluged to the computer (usb) but I have the rj45 connection off the printer pluged to the router so I can print wireless. Now I don,t know if this works with all routers, the one I am useing is a Netgear wireless router. The name "rj45" may be the incorrect name, it looks like a phone jack but a little bit bigger.

[norm.h]

My printer isn't wireless, and its only connection is USB.
Thanks for the reply, however.

[norm.h]

Got it working OK.
Printed 2 test pages and 2 pages from Open Office.
I had already allowed 631 in through the desktop (host) firewall, so I allowed 631 in & out on the laptop (client) firewall. Don't really know if that mattered, but then IPP showed up, and hadn't before.
Beyond that, I just had several tries at adding the printer to the laptop.
Thanks to all for your interest and suggestions.

[wimstock]

Thats perfect, it give me a direction in case I ever need to do the same. Take care.