quester world error

2013-07-26 16:24:26 [WARNING] [Quester] Task #79 for Quester v0.7.0-SNAPSHOT generated an exception
java.lang.IllegalArgumentException: Cannot measure distance between World_LostTemple and World
	at org.bukkit.Location.distanceSquared(Location.java:381)
	at com.gmail.molnardad.quester.utils.Region$Sphere.isWithin(Region.java:106)
	at com.gmail.molnardad.quester.objectives.RegionObjective.checkLocation(RegionObjective.java:83)
	at com.gmail.molnardad.quester.listeners.PositionListener.run(PositionListener.java:47)
	at org.bukkit.craftbukkit.v1_6_R2.scheduler.CraftTask.run(CraftTask.java:53)
	at org.bukkit.craftbukkit.v1_6_R2.scheduler.CraftScheduler.mainThreadHeartbeat(CraftScheduler.java:345)
	at net.minecraft.server.v1_6_R2.MinecraftServer.t(MinecraftServer.java:522)
	at net.minecraft.server.v1_6_R2.DedicatedServer.t(DedicatedServer.java:226)
	at net.minecraft.server.v1_6_R2.MinecraftServer.s(MinecraftServer.java:486)
	at net.minecraft.server.v1_6_R2.MinecraftServer.run(MinecraftServer.java:419)
	at net.minecraft.server.v1_6_R2.ThreadServerApplication.run(SourceFile:582)