I've got a similar problem. A while back I had the rgl_config problem, fixed it and it worked fine for a long time. Then about 3-4 months ago I bought Napoleonic Wars and ever since I haven't been able to connect to any Warband servers including native. Searched though things and tried numerous ways to fix it and none worked. Decided I want to give it another try though, as I would enjoy being able to play again. I used the network_test.exe yesterday and it worked fine. I even loaded up the cRPG mod and played that for hours without any problems. Then I shut my computer down over night and it no longer seems to work. Not only am I no longer to connect again, but when I open the multiplayer menu I get an error saying
SCRIPT ERROR ON OPCODE 1992: Invalid Mesh ID: 878; Line NO 27:
At script: add_troop_to_cur_tableau_for_profile.
At script: add_troop_to_cur_tableau_for_profile.
At script: add_troop_to_cur_tableau_for_profile.
Working fine now though.