Sorry, ignore my previous "fix", that one turned out not to be the problem.
THIS was the problem/workaround:

http://support.microsoft.com/kb/925885


Rob

"Robert Morley" <rmorley@magma.ca.N0.Freak1n.sparn> wrote in message
news:etwYZcfrHHA.5028@TK2MSFTNGP05.phx.gbl...
> Okay, I'm getting some really odd behaviour on my XP machine. Running a
> file search in advanced mode against a mapped drive, it finds no files.
> It makes no difference whether I used the mapped device or the full
> network path, I get nothing. There most certainly ARE files there, as I
> can browse to them and view them just fine.
>
> This is a fairly new computer from our IT department, so it's entirely
> possible that I've never tried a network search on this computer and
> they've set some registry key or some such thing. But I can't imagine
> them trying to forbid a network search for any reason...if that's even
> possible.
>
> I've tried re-booting, but no effect.
>
> Anybody have ANY clue what could be causing this?
>
>
>
> Rob
>