Shaky camera

[Kevin Fitch <kevin_fitch@xxxxxxxxx>]

I am trying to produce an animation where the camera folows a particular 
object, so in each frame I do something like:
     SbVec3f pt(x,y,z);
     camera->position.setValue(x+10,y+10,z+5);
     camera->pointAt(pt);
The problem is that the animation seems very 'shaky.'  So as an 
experiment I had the object sit still and the camera still shook.
Is there some kind of problem with pointAt? Or is this not an apropriate 
way to acheive my goal?
Kevin