I don't have XP so it is harder for me to test on it. However at least 2 of my beta testers have XP and it seems to work ok for them as well.
Due to the holidays I haven't had much time to code MHK, but I'll get back into the swing of things soon and see what I can do.
About 90% of the time the problem is with incorrect paths. Because you think they are correct, and they might be in a sense, they might not be what MultiHack needs/expects. If you would like, send me screenshots of your paths and I'll take a look at 'em and see if I see anything wrong.