When I registered, I tried a few names that I use on other sites, but they wee taken (it is odd to see posts from one of them, as I use it a lot, and think it is me ). Anyway, when I got to Doodledog and it was accepted, I happily registered, but didn't realise that there was a Doodle, and a Doodlebug, and possibly other members of the Doodle clan already on here.
I have been called by their names more than once, and would understand if they were irritated both by that and by the fact that I have used a name similar to theirs, but there is not a lot I can do about it now.
To be honest, when I registered, I don't think I knew about the forums - I registered to enter a competition, I think. Maybe it should be made more obvious when people sign up. If I'd known what I was doing I would have lurked for a while to get a feel for things before getting a username.