Can't set the printer I want as default printer (CUPS)

[Chris G]

I have two printers on my SoHo network, an HP7310 which is directly on
the ethernet network and an HP1320 which is shared by one of the
computers on the network.

I want to set the HP1320 Laserjet as the default printer but when I
select "set as Default" for this printer in CUPS I get an error
message saying "Unknown operation "set-as-default"!".  I can set the
HP7310 as default but that's not what I want.

So what's wrong?  I can print on the HP1320 OK, just can't set it as
default. 

-- 
Chris Green