<p>Wow, thanks for all the great responses. I did have VR on, and was resting the lens lightly on the rail of a deck. It could have been camera shake due to pressing the shutter, or as others suggested the branch may have been moving slightly. I was thinking camera shake mostly manifests itself as a blurry image, but I can see where certain conditions would cause what I was seeing.<br>
I sincerely appreciate everyone's input, especially since I wasn't expecting much of a response at all! Thanks again!</p>