OT: The only problem I have had with karma is with really long posts (aka dev journals and what not). The thumb is on the bottom of the post, but the box pops up at the top of the post. If you don't scroll back up, you can't see it... resulting in furious click click clicking of the thumbs-up button with no effect.
Edit: Please don't neg-karma me, Mr. Slinger. I'll play nice from now on. Prowmise.