You could always set your name to "Antonin_", say.
I had the same problem as you. At some point years ago, the forum choked on my name during an update or something. Probably didn't like the space in my login.
So I'm currently under a very slightly different login.
The display name is independent of your login name, BTW.
Try changing it in your personal settings.
http://www.shrapnelcommunity.com/thr...basic.php?Cat=