Ok, now first I would recommend on the first two, make sure you have up to date video drivers.
You may find the following posts setting change to be useful asis on the XP machine, however where it says "pandadx9" try "pandadx10" for the vista machine.
http://www.piratesonlineforums.com/f...60&postcount=2
As far as the other one, sounds like you need to forward some ports or something, my apologies, im not to savvy about the ports, not having had to ever adjust mine.