Disable Force Feedback under Options ->Misc
This is used to select options in the various SOIs (Helmet Hud, HUD, Left MFD, Right MFD.)
Its behaviour is dependent on where it is used.
Left / Right
Changes between weapons
Up / Down
Cycles between navigation points
Right MFD - Targeting Pod
Up / Down
Zoom in / Zoom out
TMS Right (Short)
Mark point
Forward (Short)
Toggle to zoom
Aft (Long)
Target current paypoint