Network printing failure

Mandriva 2010.1, stock kernel

Wireless router = Buffalo Nfiniti
Printer = HP all-in-one CN503B wireless

I have just entered the world of wireless networking and managed to
get my two laptops talking to the internet without any problems.  ssh
and scp worked fine from the desktop machine altair but not the other
way, from rutilicus or canopus.  That is not the specific problem here
but might have some bearing on the main problem.

The setup wizard accessed through the touchscreen panel on the printer
reported a successful connection to the LAN and the router web page on
the desktop listed the new IP and MAC addresses.  The address could be
pinged OK.  Then into CUPS to add the printer via the desktop altair.
No network printers were found so, not having a clue what to do, I
went the ipp route and specified the URI
ipp://altair:631/ipp/192.168.11.5
and the HP Printer Scanner Copier 300 hpcups 3.10.2 driver.  The test
page failed to print - unable to get printer status (Bad Request).  At
this stage I am stuck but have a feeling that the ipp address is
rubbish.  Port 9100 has been mentioned in the few posts I have been
able to locate on the web.  One says use just the IP address and the
port (9100) will be found automatically.

TIA

Len