UltraBans IPBan Error

2012-05-13 09:18:09 [INFO]  [31mUnable to find player! [0m

2012-05-13 09:18:09 [WARNING] Unexpected exception while parsing console command

org.bukkit.command.CommandException: Unhandled exception executing command 'ipban' in plugin UltraBan v0.2.7

    at org.bukkit.command.PluginCommand.execute(PluginCommand.java:42)

    at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:166)

    at org.bukkit.craftbukkit.CraftServer.dispatchCommand(CraftServer.java:479)

    at org.bukkit.craftbukkit.CraftServer.dispatchServerCommand(CraftServer.java:475)

    at net.minecraft.server.MinecraftServer.b(MinecraftServer.java:596)

    at net.minecraft.server.MinecraftServer.w(MinecraftServer.java:565)

    at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:449)

    at net.minecraft.server.ThreadServerApplication.run(SourceFile:492)

Caused by: java.lang.NullPointerException

    at com.modcrafting.ultrabans.commands.Ipban.onCommand(Ipban.java:144)

    at org.bukkit.command.PluginCommand.execute(PluginCommand.java:40)

    ... 7 more