Network Is Down - Undocumented Error with Putty/Plink?


Apologies for this strange post, I'm not sure its in the right place
but I'm really struggling with my google-foo to find the documentation
on what is going on.

The situation is that we have an employee with an Windows XP-64 box
with the latest Tortoise64 release and trying to do svn+ssh to the
office machine which will allow them to code from home.

On their borrowed 32 bit machine on the same network, everything works
fine - the connection can be established and SVN works fine over it
(using paegent for the key holding). I believe that Putty itself is
fine ssh'ing to the box from both the 32 bit and 64bit machine.

However, when using the tortoise64 the error inside of a TortoisePlink
titled screen is:

"Unable to open connection: Network Error: Network is down"

Now google is not having much fun finding documents which match that -
looking through, the only confirmed links I can find is that the error
"Network is down" seems to be returned in plink.c but I just don't
really know if this is a problem caused by Tortoise's version or if its
a general plink error. I also can't find anything on the putty website
or related problems with the "network is down" error message.

The first question is, as always, what am I doing stupid [this time]?