it is the rudders i can almost guarentee
try yanking the stick back and forth alone... you wont get the message.
i had the same with my X45... now i got CHpro pedals
for the x45 fix.... take the "dampening" and "deadband" in AH for the rudder rocker and slide them up about 1/6 - 1/5 the way up (on a 17" moniter with 1024x768 about 3/4 inches up from the bottom)