Yah - they wouldn't catch the threads at all - dropped in and dropped out. seems a couple mm too small to 'catch' - thanks for checking! I wonder what's up with that.
Something is wrong - either the attys threads or the connection on the GGTS. However, if your 510's screw right on I would say its the attys. Shoot Cisco an e-mail explaining. I had to send back 1-306 that would not screw on the Phidius. Hole was too small. Also back in December there was a shipment of 901's that were defective and would not screw on to any mod I owned. Ended up the whole bunch that he got in were no good.