Bukkit

What steps will reproduce the problem?
1. Leader of the party is offline
2. "/skyblock home" command
3. internal server error - null pointer on hasIsland method line #535

What is the expected output? What do you see instead?
homing <-> internal error (as mentioned above)

What version of the product are you using?
1.5.1

Do you have an error log of what happened?
>18:57:19 [INFO] * issued server command: /sb home
>18:57:19 [SEVERE] null
org.bukkit.command.CommandException: Unhandled exception executing command 'sb' in plugin SkyBlockCo-Op v1.5
at org.bukkit.command.PluginCommand.execute(PluginCommand.java:46)
at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:186)
at org.bukkit.craftbukkit.v1_4_6.CraftServer.dispatchCommand(CraftServer.java:514)
at net.minecraft.server.v1_4_6.PlayerConnection.handleCommand(PlayerConnection.java:979)
at net.minecraft.server.v1_4_6.PlayerConnection.chat(PlayerConnection.java:897)
at net.minecraft.server.v1_4_6.PlayerConnection.a(PlayerConnection.java:852)
at net.minecraft.server.v1_4_6.Packet3Chat.handle(Packet3Chat.java:44)
at net.minecraft.server.v1_4_6.NetworkManager.b(NetworkManager.java:290)
at net.minecraft.server.v1_4_6.PlayerConnection.d(PlayerConnection.java:112)
at net.minecraft.server.v1_4_6.ServerConnection.b(SourceFile:39)
at net.minecraft.server.v1_4_6.DedicatedServerConnection.b(SourceFile:30)
at net.minecraft.server.v1_4_6.MinecraftServer.r(MinecraftServer.java:598)
at net.minecraft.server.v1_4_6.DedicatedServer.r(DedicatedServer.java:224)
at net.minecraft.server.v1_4_6.MinecraftServer.q(MinecraftServer.java:494)
at net.minecraft.server.v1_4_6.MinecraftServer.run(MinecraftServer.java:427)
at net.minecraft.server.v1_4_6.ThreadServerApplication.run(SourceFile:849)
Caused by: java.lang.NullPointerException
at nz.Tzeentchful.SkyBlock.IslandManager.hasIsland(IslandManager.java:535)
at nz.Tzeentchful.SkyBlock.SkyblockCommand.onCommand(SkyblockCommand.java:77)
at org.bukkit.command.PluginCommand.execute(PluginCommand.java:44)
... 15 more

Please provide any additional information below.
That pretty much concludes it.