The world border on the survival server was recently removed, due to this Dynmap (formerly survival.plasmagc.com) has been filling up the diskspace on the server, to the point where it could of resulted in a world reset. Therefore dynmap will be removed. It's a good tool but has a big load on the server. The border will come back, but in an expanded form. The server will still be monitored to see if it can handle with a bigger border.
Minecraft Game Manager & Moderator