Enterprise Manager over a VPN gets No items

I have an environment that has 18 separate SQL server machines. When
connected to the LAN I can connect to each and expand the databases tab no
problem. When I try the same over a VPN I find that three of my servers will
connect but on expanding the databases I get a long pause then 'No items'.
I've checked around and found some references to the same problem (SQL
server mag site) but no resolutions. I'm running XP pro and my SQL is sp3.
The three servers in question have only TCP and named pipes in the net lib,
they are all on Win2K one is on sp3, one on sp2 and one is 'out of the box'.
The VPN has ports 1433 and 1434 udp and tcp allowed.

Does anyone have any suggestions as to what is causing this, its got to be
something simple but I've been looking at this so long now I cant see the
wood for the trees.

Help appreciated.There is a least one known issue that can produce this:

http://support.microsoft.com/default.aspx?scid=kb;[LN];Q315523

Here are some comments from an MS engineer on it:

http://groups.google.ch/groups?hl=e...%40cpmsftngxa06

There are several Google groups hits on this, by the way:

http://groups.google.com/groups?hl=...ems&sa=N&tab=wg

Simon

"Simon" <spamplin@.hss.com> wrote in message
news:bdpe27$k71$1@.hercules.btinternet.com...
> I have an environment that has 18 separate SQL server machines. When
> connected to the LAN I can connect to each and expand the databases tab no
> problem. When I try the same over a VPN I find that three of my servers
will
> connect but on expanding the databases I get a long pause then 'No items'.
> I've checked around and found some references to the same problem (SQL
> server mag site) but no resolutions. I'm running XP pro and my SQL is sp3.
> The three servers in question have only TCP and named pipes in the net
lib,
> they are all on Win2K one is on sp3, one on sp2 and one is 'out of the
box'.
> The VPN has ports 1433 and 1434 udp and tcp allowed.
> Does anyone have any suggestions as to what is causing this, its got to be
> something simple but I've been looking at this so long now I cant see the
> wood for the trees.
> Help appreciated.