In 2.77a, the 2D Stabilize is causing stretched pixel artifacts all along the edges that black. This problem is particularly strong when animating the Location Influence and Scale Influence. The artefacts are present in renders, as well as in the Movie Clip Editor with Display Stabilization turned on.
As you can see, on the top edge and left edge, the pixels are stretched to the edges, as if trying to fill the black gap that would be left there. I had to black out the faces of the actors, as we are still in post. Furthermore, these artefacts appear no matter what when animating the Location and Scale Influences in the Movie Clip Editor. Previewing the animated stabilization is impossible, also, because the influences do not update with each frame. You have to refresh something in the Movie Clip Editor for it to show its true position (like turning 2D Stabilization off and on).
Is this a bug, or am I missing something?