Thanks to all who emailed both on and offlist. I've been advised that there were definately multiple people from NANOG affected (aka 'subscribed')by the google groups thing and that Google were promptly been heads-upped by some kind soul on NANOG who have since zapped the group concerned into a fine powder. As for the dupe-delivery issue, Google have made contact and are looking into it now. It does appear based on feedback that it has been seen before, but infrequently. If anything else comes of it i'll feed back to the list if anyone would be interested. Regards Mark.