Bukkit

What is the issue?
I made an arena and it worked perfectly, (apart from the ice melting at sometimes), I reloaded the server cause I got a different plugin, then I went to play colour shuffle again and my join sign said Arena Closed, so when I tried to open it, it said it couldn't find that arena, then I did the list arenas command and it wasn't there, Its easy to setup the arena but I don't really want to do this everytime if it is the case.

Please provide any additional information below.