Search the forum on how to take pictures of beamshots and take one of your beam.
My PD30 doesn't have the "cree rings" nor a single dark shadow.
err.. Wait, actually it's barely noticable.
Take a picture anyway as it might be overly obsessive and it would mean there is a problem because it's not supposed to do that.
However, after a few days of use it might fade into oblivion as you stop shinning it on walls so much