I have the same problems, they are solved easily by using alt+tab though.

Another sucky thing here, and notonly with XP: often after entering a chatmessage and sending it, my JJ2 freezes a short time. Sometimes longer, sometimes less long. Mostly if many people are in my server...but this oughta be impossible, because I have a P4 2,53....I wonder why. Anyone knows a solution?