minecraft freeze log

STDERR] at aam.a(AnvilChunkLoader.java:83)
2013-04-01 21:22:23 [INFO] [STDERR] at im.f(ChunkProviderServer.java:182)
2013-04-01 21:22:23 [INFO] [STDERR] at im.c(ChunkProviderServer.java:118)
2013-04-01 21:22:23 [INFO] [STDERR] at net.minecraft.server.MinecraftServer.e(MinecraftServer.java:310)
2013-04-01 21:22:23 [INFO] [STDERR] at bdz.a(IntegratedServer.java:84)
2013-04-01 21:22:23 [INFO] [STDERR] at bdz.c(IntegratedServer.java:101)
2013-04-01 21:22:23 [INFO] [STDERR] at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:458)
2013-04-01 21:22:23 [INFO] [STDERR] at fy.run(SourceFile:849)
2013-04-01 21:22:23 [INFO] [STDOUT] Wrong location! qc['Creeper'/1669, l='FeedTheBeast LP', x=-29.70, y=39.23, z=-138.30]
2013-04-01 21:22:23 [INFO] [STDERR] java.lang.Exception: Stack trace
2013-04-01 21:22:23 [INFO] [STDERR] at java.lang.Thread.dumpStack(Unknown Source)
2013-04-01 21:22:23 [INFO] [STDERR] at zz.a(Chunk.java:923)
2013-04-01 21:22:23 [INFO] [STDERR] at aam.a(AnvilChunkLoader.java:406)
2013-04-01 21:22:23 [INFO] [STDERR] at aam.a(AnvilChunkLoader.java:103)
2013-04-01 21:22:23 [INFO] [STDERR] at aam.a(AnvilChunkLoader.java:83)
2013-04-01 21:22:23 [INFO] [STDERR] at im.f(ChunkProviderServer.java:182)
2013-04-01 21:22:23 [INFO] [STDERR] at im.c(ChunkProviderServer.java:118)
2013-04-01 21:22:23 [INFO] [STDERR] at net.minecraft.server.MinecraftServer.e(MinecraftServer.java:310)
2013-04-01 21:22:23 [INFO] [STDERR] at bdz.a(IntegratedServer.java:84)