iSeries Navigator's Database component doesn't show on W2K, does on XP

Hi there, and Happy New Year to everyone.

It's been quite a while since I contributed (or even lurked) here, but a
problem has now come up that I can't find a solution for anywhere, despite
comprehensive searching of the web, Usenet and of course the Midrange.com
archives..

In iSeries Navigator, when I connect to one machine, the Database element
(what do you call part of a tree view: a branch? a leaf?) does not appear.
I think this may have been true since we upgraded the machine to V5R3, but
it hasn't really mattered until now.

The odd thing is that if I connect to another machine (which is actually
another logical partition on the same physical machine) I do see the
Database element.  And there is one user who, if he connects to the machine
that I am having trouble with, does see Database.  That user's profile has
*ALLOBJ, so I thought it might be an authority issue.  So I tried connecting
as a *SECOFR class user; and I still didn't see Database.

However, when the other user connects using my PC, he does not see the
Database element.  The difference between our machines is that he has
Windows XP, while I have 2000.  Both installations of iSeries Access are at
Service Level SI16496, which matches the iSeries.

I found the following thread in the archives:
http://archive.midrange.com/midrange-l/200211/msg00594.html, which describes
a similar, though not identical, problem back at V5R1.  The solution there
was to selectively remove and then reinstall the Database component of Ops
Nav, so I tried doing that.  But it didn't fix it.

Note also that Application Administration for the machine in question shows
the Database component (right between "Users and Groups" and "File Systems")
with all the default options checked, which should allow it for all users.

I should also point out that this is not just my PC or my user profile: I'm
actually looking into this for a colleague who is not so familiar with the
iSeries.  He also has Windows 2000, and the same problem as me.

So it's clearly a combination of something on the iSeries (since I can see
the Database element when connecting to another partition) and something on
the PC.

I'd be grateful for any ideas.  And while "upgrade to XP" is one that might
solve the problem, it's a bit of a sledgehammer.

Cheers,

Martin.