I'm not aware of any remaining issues regarding RaR not working on some computers. It did have a problem with icons being black at some point, but I found the cause for that one and it has been fixed in a recent release. If you have a problem, then I would like to hear more about it. Also I have worked hard on improving network stability in RaR (though it wasn't bad when I started). If people can manage to desync the game, then I would like to hear about that as well, particularly if you can figure out how to make it desync (like every time you press a certain button or something).