Got myself a 14-24mm. Is this sound normal?

My E just received a nice addition with the Nikon 14-24mm lens. Overall it is impressive, although I think I might have a back/front- focusing issue that I'll need to check for.

I noticed a weird sound during focusing. Is this normal? Do you have similar noise while focusing your lens?

Here's a sample:

http://www.youtube.com/watch?v=t_a6BX9aZLQ

Your comments are appreciated.

Thanks.
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