I just upgraded from 13w38b to 13w38c and now when I start my server I see the following errors.

2013-09-20 15:26:05 [INFO] Preparing start region for level 0
2013-09-20 15:26:06 [SEVERE] Item entity 21 has no item?!
s: Loading entity NBT
at om.f(SourceFile:1070)
at os.a(SourceFile:149)
at afy.a(SourceFile:287)
at afy.a(SourceFile:76)
at afy.a(SourceFile:64)
at km.f(SourceFile:115)
at km.c(SourceFile:66)
at net.minecraft.server.MinecraftServer.g(SourceFile:224)
at net.minecraft.server.MinecraftServer.a(SourceFile:194)
at jn.e(SourceFile:182)
at net.minecraft.server.MinecraftServer.run(SourceFile:313)
at jc.run(SourceFile:581)
Caused by: java.lang.NullPointerException
at pn.b(SourceFile:134)
at tt.a(SourceFile:241)
at tt.a(SourceFile:185)
at om.f(SourceFile:1063)
... 11 more
2013-09-20 15:26:06 [INFO] Preparing spawn area: 15%
2013-09-20 15:26:07 [SEVERE] Item entity 337 has no item?!
s: Loading entity NBT
at om.f(SourceFile:1070)
at os.a(SourceFile:149)
at afy.a(SourceFile:287)
at afy.a(SourceFile:76)
at afy.a(SourceFile:64)
at km.f(SourceFile:115)
at km.c(SourceFile:66)
at net.minecraft.server.MinecraftServer.g(SourceFile:224)
at net.minecraft.server.MinecraftServer.a(SourceFile:194)
at jn.e(SourceFile:182)
at net.minecraft.server.MinecraftServer.run(SourceFile:313)
at jc.run(SourceFile:581)
Caused by: java.lang.NullPointerException
at pn.b(SourceFile:134)
at tt.a(SourceFile:241)
at tt.a(SourceFile:185)
at om.f(SourceFile:1063)
... 11 more
2013-09-20 15:26:07 [INFO] Preparing spawn area: 79%
2013-09-20 15:26:08 [INFO] Done (2.588s)! For help, type "help" or "?"