Moving Dropped Torch

I was working on my group's adventure map when I noticed a dropped torch behaving strangely. I made a video of said glitch (not by recreating, the original) http://www.youtube.com/watch?v=UXVddoOeBwE

Scenario: I was working in creative mode when I accidentally broke a block with a torch on it. I replaced the block and moved on. I came back to add some lighting and I noticed the torch behaving strangely on the ground, moving back and forth across cobblestone half-slabs. I can provide more details if necessary at shredswab101@aol.com or at Minecraftforum.net under the name Shreddykickflip.