Sharing Printers Setup Problem

[THGeorge]

Two debian boxes - one lenny, one etch, each with its own printer  -
connected to the LAN and can ping each other.

Problem: Etch box can use Lenny box's printer, Lenny Box cannot find or
stalls trying to use Etch box's printer.

More precisely, if I run lynx localhost:631 on the Lenny box and tell
cups to find new printers it finds none and if I use cups to add Etch
box's printer using the correct ipp address it does so but when I try to
print a test page it stalls with the message:

"recoverable: Network host '192.168.2.105' is busy, will try again in 20
seconds"

Allowing for the different releases of cups on the two systems I believe
I have set up the two versions of cupsd.conf consistently.  hosts.allow
are also consistent.

Any suggestions as to where the problem might lie?

Tom