Welcome, LadyLurker! That does seem the most likely answer, yes. Moderators are able to see your IP address, and they are able to check if any other usernames are also associated with that IP. And since many people here have several accounts, it is usually assumed that one IP address equals one person. Of course there are exceptions - family members sharing the same internet connections, for example. But more often than not, a new account with an already familiar IP address means that somebody got themselves another "sock", as we call them. I think you were simply caught up in a little mix-up.