Should this be happening?

[np2004]

This is my first Suv an 08 4.8i I just picked up about two weeks ago. Coming from a 330ci I recently noticed when at highway speeds even the slightest amount of wind makes the X5 blow from side to side making it tough to stay in my highway lane. Is this normal since this is an Suv? or is this a sign of an alignment problem which is made worse in the wind? I always assumed even though it sits higher than a car which makes it more vunerable to wind and less aerodynamic that the added weight of the vehicle would make it even more stable at highway speeds in the wind.