GroupManager /manload Error

2012-04-14 18:42:39 [WARNING] Unexpected exception while parsing console command

org.bukkit.command.CommandException: Unhandled exception executing command 'manload' in plugin GroupManager v2.0.8 (Phoenix)

    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:473)

    at org.bukkit.craftbukkit.CraftServer.dispatchServerCommand(CraftServer.java:469)

    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.util.ConcurrentModificationException

    at java.util.WeakHashMap$HashIterator.nextEntry(WeakHashMap.java:785)

    at java.util.WeakHashMap$KeyIterator.next(WeakHashMap.java:818)

    at org.anjocaido.groupmanager.permissions.BukkitPermissions.removeAllAttachments(BukkitPermissions.java:375)

    at org.anjocaido.groupmanager.GroupManager.onDisable(GroupManager.java:111)

    at org.anjocaido.groupmanager.GroupManager.onCommand(GroupManager.java:1591)

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

    ... 7 more