I am at a loss here as I don't really know what's happening. I think maybe your top and bottom standards may be dirty where they meet the turntable. Can you take them off and clean them to make sure there is no residue on them. I think your best bet would be to call Alpha and talk to them. Was this a used or new machine when you bought it?
I would like to apologize to anyone I have not offended. Please be patient I will get to you shortly.