Bukkit

What steps will reproduce the problem?
1. Installed as a plugin
2. At console did a seen help
3.

What is the expected output? What do you see instead?
Got error messages see below

What version of the product are you using?
Version 1.3
This server is running CraftBukkit version git-Bukkit-1.2.4-R1.0-b2126jnks (MC: 1.2.4) (Implementing API version 1.2.4-R1.0)

Do you have an error log of what happened?
>seen help
14:18:54 [WARNING] Unexpected exception while parsing console command
org.bukkit.command.CommandException: Unhandled exception executing command 'seen' in plugin Seen v1.3
        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:599)
        at net.minecraft.server.MinecraftServer.w(MinecraftServer.java:568)
        at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:452)
        at net.minecraft.server.ThreadServerApplication.run(SourceFile:490)
Caused by: java.lang.ClassCastException: org.bukkit.craftbukkit.command.ColouredConsoleSender cannot be cast to org.bukkit.entity.Player
        at net.h31ix.assistant.Assistant$1.onCommand(Assistant.java:48)
        at org.bukkit.command.PluginCommand.execute(PluginCommand.java:40)
        ... 7 more

Please provide any additional information below.
Hoping this is a temporary problem. Am assuming it does not need permission settings ? Also that it is compatible with other plugins the full list I have is

[INFO] Plugins (14): Seen, Spectate, tMOTD, DragonTravel, Permissions, VanishNoPacket, PermissionsBukkit, eTeleport, SimpleChestLock, ForceField, Hawk, ChangeGameMode, MyWolf, Lift