Alun
Under Dungeness you have not posted a reply, are you saying there is no spot on your envelope, if so this is correct. The thread envelope will not be marked on your machine until you have posted a reply. I think the idea of spots is to mark threads you have contributed to assist in keeping track of where you have posted.
Update: I hadn't posted in that thread and had no dot, posted and a dot appeared, deleted post and spot dissapeared. Problem solved....I think
Martin