really strange remote access to WSS through a VPN connection...

Hi,

first point: I don't know where exactly I have to post this question...
Second: my problem is related to sharepoint...

I have a server deployed. To access it I'm using a cisco VPN client.
Due to some conflicts, I'm using a virtual machine as a bridge between my
local network and the client network. And I have statics routes to redirect
the trafic through this VPN connection.

All works fine, I can access sharepoint and play with it.
But the problems appear when I try to upload a file using the attachment
option of a task item for example, or when I try to save a page using
FP2003.

In these cases, my VPN connection freeze for a few seconds and I receive a
time out error!!!!
I really don't know what's appends and why only during these 2 operations???

I have try to change the port used to access my server without more result.
From my virtual machine, I do the same job without any problem.
Publishing an image from FP2003 for example don't crash, but saving the
dafult.aspx page after I have modify it crash!!!

So I really don't know where to post this and what can I do.
So maybe a guy has a way for me?

Thanks for your guides.

Jerome.