I crashed when I trade with a villager in the newest snapshot
this is the crash report: for some reason it did not let me send it to mojang
but I am using an vanilla version of minecraft

---- Minecraft Crash Report ----
// I let you down. Sorry

Time: 5-10-13 19:47
Description: Ticking memory connection

java.lang.NullPointerException
at acs.a(SourceFile:55)
at vb.a(SourceFile:292)
at wz.a(SourceFile:58)
at vx.a(SourceFile:238)
at kv.a(SourceFile:649)
at fs.a(SourceFile:32)
at eb.b(SourceFile:63)
at kv.e(SourceFile:69)
at ky.b(SourceFile:40)
at box.b(SourceFile:83)
at net.minecraft.server.MinecraftServer.u(SourceFile:494)
at net.minecraft.server.MinecraftServer.t(SourceFile:411)
at bou.t(SourceFile:121)
at net.minecraft.server.MinecraftServer.run(SourceFile:346)
at jc.run(SourceFile:582)

A detailed walkthrough of the error, its code path and all known details is as follows:
---------------------------------------------------------------------------------------

– Head –
Stacktrace:
at acs.a(SourceFile:55)
at vb.a(SourceFile:292)
at wz.a(SourceFile:58)
at vx.a(SourceFile:238)
at kv.a(SourceFile:649)
at fs.a(SourceFile:32)
at eb.b(SourceFile:63)
at kv.e(SourceFile:69)

– Ticking connection –
Details:
Connection: kv@19bf878
Stacktrace:
at ky.b(SourceFile:40)
at box.b(SourceFile:83)
at net.minecraft.server.MinecraftServer.u(SourceFile:494)
at net.minecraft.server.MinecraftServer.t(SourceFile:411)
at bou.t(SourceFile:121)
at net.minecraft.server.MinecraftServer.run(SourceFile:346)
at jc.run(SourceFile:582)

– System Details –
Details:
Minecraft Version: 13w39b
Operating System: Windows XP (x86) version 5.1
Java Version: 1.7.0_25, Oracle Corporation
Java VM Version: Java HotSpot(TM) Client VM (mixed mode), Oracle Corporation
Memory: 175320584 bytes (167 MB) / 381202432 bytes (363 MB) up to 1037959168 bytes (989 MB)
JVM Flags: 2 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx1G
AABB Pool Size: 1249 (69944 bytes; 0 MB) allocated, 551 (30856 bytes; 0 MB) used
IntCache: cache: 0, tcache: 0, allocated: 0, tallocated: 0
Profiler Position: N/A (disabled)
Vec3 Pool Size: 86 (4816 bytes; 0 MB) allocated, 67 (3752 bytes; 0 MB) used
Player Count: 1 / 8; [kq['Huntondoom'/528, l='Zombie_Survival', x=-194,70, y=71,00, z=188,08]]
Type: Integrated Server (map_client.txt)
Is Modded: Probably not. Jar signature remains and both client + server brands are untouched.