shining, if you mentioned this already, I didn't see it, so I apologize if asking something you already answered...
If you are in windows, and go into start->control panel->game controllers and then properties on your X52. Does the joystick look like it's acting fine in there? Move the stick around and watch the + on the X and Y axis, as well as the Z and throttle... make sure it moves pretty smoothly without a lot of huge jumps.
If everything looks good in there, then in AH, when you're in the "Stick Setup", make sure all 10 sliders for roll, pitch, and rudder on the left hand side are at 100% (the top). Seems like an odd thing, but my X52 had a LOT of bounce when trying to move until I did that, and now it's much much easier to use.
If everything does NOT look good in that game controllers panel, then my though is maybe your USB port has a problem of some kind. I'm not sure if the X52 is USB2.0 or USB1.1, but that could make a difference. Perhaps try different USB ports, or see if your motherboard has updated USB drivers.
Just some thoughts and again, sorry if any of it is a repeat.