I am having similar problems with TrackIR. If I leave the cockpit view at it default position I have no shake, but if I zoom in or out of the default zone I get shake like my point of view is moving front to back about an inch or two but no side to side shake.
I have my cockpit zoom mapped to the joystick throttle axis and have put some deadzone into that axis, that eliminated some of the shake but not all.
I am still working the problem If I find a cure I will post it.
Jim