Just in case someone finds this thread looking for a solution: I had exactly the same problem - AIM9 and HARMs going off in pairs or even triples. Had stick, throttle and pedals plugged into an USB hub, mostly for ease of setup/storage. First solution I tried was using a different hub, which did not solve the issue. What did solve the issue was pluging the stick into a dedicated USB port, front panel one in my case. Since then the issue is gone - I waited a couple of days and sorties before posting here to be absolutely sure. As I understand it, there may be some hub-like ports even on a mainboard proper, so even if the first port does not solve your issues, try a different one, maybe.