Well, a few observations. I have set Dude up on a FC5 server with the server running there under wine.
If I use Dude client on the FC5 server, everything works. Link info on the map is updated, and if you cursor over the device it will display the graph.
If I use Dude client on a Windows box and connect to the FC5 server running the Dude server, it works fine.
If I use Dude client on another FC5 box and connect to Dude server on the FC5 server, it will draw the map and put the links in correctly. But after the initial values in the links, it never updates them again. Also if I cursor over a device it will show the loading chart but that is as far as it gets.
I am using RC9.
tk