Win XP - 'Passthrough' Auth From Domain Member to Workgroup Fails

Hi

I have a problem with my XP SP2 domain member computer, which refuses to use
'pass through' authentication to non-domain member PCs.

To clarify, what I call 'pass through' is when you create an account on a
standalone PC or workstation with the same username and password as your
domain account.

This allows you to connect to SQL/shares etc on the stand-alone server or
client without having to enter credentials.

I have access to several servers and workstations, all of which work fine
with this. My laptop fails - it pops up an authentication box, and if I enter
my (unqualified) username and password it informs me that this username has
already been tried.

If I enter the username in the format
StandAloneWorkstationHostnameOrIP\username, it connects, ruling out any
password discrepancies.

It seems my workstation is just not attempting to pass through the
credentials - if I set failure audit on logon events on the other workstation
I see nothing unless I enter bad credentials deliberately.

Any suggestions?

Aaron