I have some problems with minecraft the blocks come back

after it got glitch it showed this

---- Minecraft Crash Report ----
// Shall we play a game?

Time: 5/21/13 10:44 AM
Description: Sending packet

java.lang.NullPointerException
	at ch.b(SourceFile:107)
	at ch.a(SourceFile:39)
	at jh.b(SourceFile:430)
	at je.a(SourceFile:218)
	at je.a(SourceFile:202)
	at it.a(SourceFile:127)
	at net.minecraft.server.MinecraftServer.r(SourceFile:470)
	at net.minecraft.server.MinecraftServer.q(SourceFile:397)
	at bjg.q(SourceFile:122)
	at net.minecraft.server.MinecraftServer.run(SourceFile:331)
	at gp.run(SourceFile:573)


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

-- Head --
Stacktrace:
	at ch.b(SourceFile:107)
	at ch.a(SourceFile:39)

-- Packet being sent --
Details:
	Packet ID: 35
	Packet class: es
Stacktrace:
	at jh.b(SourceFile:430)
	at je.a(SourceFile:218)
	at je.a(SourceFile:202)
	at it.a(SourceFile:127)
	at net.minecraft.server.MinecraftServer.r(SourceFile:470)
	at net.minecraft.server.MinecraftServer.q(SourceFile:397)
	at bjg.q(SourceFile:122)
	at net.minecraft.server.MinecraftServer.run(SourceFile:331)
	at gp.run(SourceFile:573)

-- System Details --
Details:
	Minecraft Version: 1.5.2
	Operating System: Windows Vista (x86) version 6.0
	Java Version: 1.7.0_21, Oracle Corporation
	Java VM Version: Java HotSpot(TM) Client VM (mixed mode), Oracle Corporation
	Memory: 270418520 bytes (257 MB) / 775954432 bytes (740 MB) up to 1037959168 bytes (989 MB)
	JVM Flags: 2 total; -Xms512m -Xmx1024m
	AABB Pool Size: 92612 (5186272 bytes; 4 MB) allocated, 92612 (5186272 bytes; 4 MB) used
	Suspicious classes: No suspicious classes found.
	IntCache: cache: 0, tcache: 0, allocated: 3, tallocated: 63
	Profiler Position: N/A (disabled)
	Vec3 Pool Size: 6909 (386904 bytes; 0 MB) allocated, 6909 (386904 bytes; 0 MB) used
	Player Count: 1 / 8; [jc['Dragonages1'/19743, l='New World', x=82.52, y=49.00, z=333.32]]
	Type: Integrated Server (map_client.txt)
	Is Modded: Probably not. Jar signature remains and both client + server brands are untouched.