VM client can't access CUPS printer

[Steve Kleene <skdeb@syrano.acb.uc.edu>]

I have a Wheezy host with a USB printer and a virtualbox XP client.  The VM
(client) is unable to access the CUPS printer.  In XP, I have tried URLs of
this form in defining a network printer:

  http://URL:631/printers/Phaser_6280DN

where URL is any one of the following:

  10.97.14.132 (host IP, from ifconfig -a)
  10.0.2.2 (default gateway of VM, from ipconfig /all)
  localhost
  127.0.0.1

The VM can ping all four of those addresses.  "Phaser_6280DN" is the name of
the host's CUPS printer.  When I enter any of the above URLs, the VM says:

"Windows cannot connect to the printer.  Either the printer name was typed
incorrectly, or the specified printer has lost its connection to the
server."

With iceweasel on the host, either of these URLs

  http://localhost:631/printers/Phaser_6280DN
  http://127.0.0.1:631/printers/Phaser_6280DN

brings up the CUPS printer definition.  I've found no way to do that from the
client's Explorer.  The CUPS printer works OK from the host.

Wheezy and virtualbox are both up-to-date, including the guest additions and
extension pack.  I have the same host/client pair at home with a CUPS
parallel printer.  The client printer definition there includes the host IP,
and that works.  From the client, I can print and also bring up the printer
definition in Explorer under host_IP:631.  In both setups, I am using the
same cupsd.conf and NAT.  Any ideas what the problem is?

Thanks.