Bukkit

i installed this backpack mod http://dev.bukkit.org/bukkit-plugins/backpacks/ and updated the server jar to the new 1.7.2 beta build r.3
and now when ever i try spec someone being the owner/op/*.* perm node the server spams this error. but my moderators can spec without any problems any idea whats wrong here?
[Server thread/INFO]: GENERAL69LEMONZ issued server command: /spec ErazePlaysMC
[17:45:21] [Server thread/ERROR]: null
org.bukkit.command.CommandException: Unhandled exception executing command 'spec' in plugin Spectate v2.0
    at org.bukkit.command.PluginCommand.execute(PluginCommand.java:46) ~[Server.jar:git-Bukkit-1.7.2-R0.3-b3020jnks]
    at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:175) ~[Server.jar:git-Bukkit-1.7.2-R0.3-b3020jnks]
    at org.bukkit.craftbukkit.v1_7_R1.CraftServer.dispatchCommand(CraftServer.java:683) ~[Server.jar:git-Bukkit-1.7.2-R0.3-b3020jnks]
    at net.minecraft.server.v1_7_R1.PlayerConnection.handleCommand(PlayerConnection.java:952) [Server.jar:git-Bukkit-1.7.2-R0.3-b3020jnks]
    at net.minecraft.server.v1_7_R1.PlayerConnection.a(PlayerConnection.java:814) [Server.jar:git-Bukkit-1.7.2-R0.3-b3020jnks]
    at net.minecraft.server.v1_7_R1.PacketPlayInChat.a(PacketPlayInChat.java:28) [Server.jar:git-Bukkit-1.7.2-R0.3-b3020jnks]
    at net.minecraft.server.v1_7_R1.PacketPlayInChat.handle(PacketPlayInChat.java:47) [Server.jar:git-Bukkit-1.7.2-R0.3-b3020jnks]
    at net.minecraft.server.v1_7_R1.NetworkManager.a(NetworkManager.java:146) [Server.jar:git-Bukkit-1.7.2-R0.3-b3020jnks]
    at net.minecraft.server.v1_7_R1.ServerConnection.c(SourceFile:134) [Server.jar:git-Bukkit-1.7.2-R0.3-b3020jnks]
    at net.minecraft.server.v1_7_R1.MinecraftServer.u(MinecraftServer.java:655) [Server.jar:git-Bukkit-1.7.2-R0.3-b3020jnks]
    at net.minecraft.server.v1_7_R1.DedicatedServer.u(DedicatedServer.java:250) [Server.jar:git-Bukkit-1.7.2-R0.3-b3020jnks]
    at net.minecraft.server.v1_7_R1.MinecraftServer.t(MinecraftServer.java:545) [Server.jar:git-Bukkit-1.7.2-R0.3-b3020jnks]
    at net.minecraft.server.v1_7_R1.MinecraftServer.run(MinecraftServer.java:457) [Server.jar:git-Bukkit-1.7.2-R0.3-b3020jnks]
    at net.minecraft.server.v1_7_R1.ThreadServerApplication.run(SourceFile:617) [Server.jar:git-Bukkit-1.7.2-R0.3-b3020jnks]
Caused by: java.lang.IllegalArgumentException: Health must be between 0 and 20.0
    at org.bukkit.craftbukkit.v1_7_R1.entity.CraftLivingEntity.setHealth(CraftLivingEntity.java:81) ~[Server.jar:git-Bukkit-1.7.2-R0.3-b3020jnks]
    at com.Chipmunk9998.Spectate.api.SpectateManager.startSpectating(SpectateManager.java:235) ~[?:?]
    at com.Chipmunk9998.Spectate.SpectateCommandExecutor.onCommand(SpectateCommandExecutor.java:324) ~[?:?]
    at org.bukkit.command.PluginCommand.execute(PluginCommand.java:44) ~[Server.jar:git-Bukkit-1.7.2-R0.3-b3020jnks]
    ... 13 more