Fsx trim problem

Hello,

So I have been playing fsx for a while and recently i formated my pc and reinstalled fsx. Now when I play using addon aircraft, when I try to use mouse look the aircraft starts trimming down. I decided to see why it was happening and tried binding the trim controls to toatally different keys and it still trims, it even trims in mouse yoke. I have searched everywhere and could not find anything. If you can help please tell me.

Thanks