Since you restarted the server, i have been getting an error report that makes my client crash when connecting, it says: "Minecraft has stopped running because it encountered a problem; Ticking screen". it seems like the error has something to do with world loading. I can provide the whole error message if it's necessary.
The server seems to crash every time i go towards a redstone torch, which is a few hundred blocks away from spawn. I heard the noises used in sonic and hypersonic explosives once i got closer. but before blocks start flying up, the server crashes... Seems like i simply have to stay away from there :S