Guys when I play MC, after a few minutes it crashes and shows this error:

Minecraft has crashed!
----------------------

Minecraft has stopped running because it encountered a problem; Unexpected error
This error has been saved to C:UsersJoel I. MartinezAppDataRoaming.minecraftcrash-reportscrash-2012-10-28_11.15.37-client.txt for your convenience. Please include a copy of this file if you report this crash to anyone.

--- BEGIN ERROR REPORT b3a450a7 --------
Generated 10/28/12 11:15 AM

- Minecraft Version: 1.4.2
- Operating System: Windows 7 (x86) version 6.1
- Java Version: 1.7.0_06, Oracle Corporation
- Java VM Version: Java HotSpot(TM) Client VM (mixed mode), Oracle Corporation
- Memory: 407096792 bytes (388 MB) / 519110656 bytes (495 MB) up to 1037959168 bytes (989 MB)
- JVM Flags: 2 total; -Xms512m -Xmx1024m
- AABB Pool Size: 2598 (145488 bytes; 0 MB) allocated, 104 (5824 bytes; 0 MB) used
- LWJGL: 2.4.2
- OpenGL: Intel Pineview Platform GL version 1.4.0 - Build 8.14.10.2117, Intel
- Is Modded: Probably not
- Type: Client
- Texture Pack: Default
- Profiler Position: N/A (disabled)
- Vec3 Pool Size: 1628 (91168 bytes; 0 MB) allocated, 24 (1344 bytes; 0 MB) used
- World MpServer Entities: 9 total; [axc['mineruhs83'/256942, l='MpServer', x=2019.83, y=64.62, z=-2751.85], qa['Zombie'/256980, l='MpServer', x=1941.47, y=12.00, z=-2718.03], pw['Skeleton'/256979, l='MpServer', x=1943.16, y=31.00, z=-2728.50], pw['Skeleton'/256978, l='MpServer', x=1951.86, y=30.00, z=-2773.89], qa['Zombie'/256977, l='MpServer', x=1945.50, y=35.00, z=-2821.50], pw['Skeleton'/256976, l='MpServer', x=1947.50, y=35.00, z=-2827.50], pl['Creeper'/256991, l='MpServer', x=1974.22, y=66.00, z=-2698.38], qa['Zombie'/257034, l='MpServer', x=2084.13, y=37.00, z=-2826.47], qa['Zombie'/-2147483646, l='MpServer', x=209.00, y=63.00, z=367.00]]
- World MpServer Players: 1 total; [axc['mineruhs83'/256942, l='MpServer', x=2019.83, y=64.62, z=-2751.85]]
- World MpServer Chunk Stats: MultiplayerChunkCache: 169
- Forced Entities: 9 total; [axc['mineruhs83'/256942, l='MpServer', x=2019.83, y=64.62, z=-2751.85], qa['Zombie'/-2147483646, l='MpServer', x=209.00, y=63.00, z=367.00], qa['Zombie'/256980, l='MpServer', x=1941.47, y=12.00, z=-2718.03], pw['Skeleton'/256979, l='MpServer', x=1943.16, y=31.00, z=-2728.50], pw['Skeleton'/256978, l='MpServer', x=1951.86, y=30.00, z=-2773.89], qa['Zombie'/256977, l='MpServer', x=1945.50, y=35.00, z=-2821.50], pw['Skeleton'/256976, l='MpServer', x=1947.50, y=35.00, z=-2827.50], pl['Creeper'/256991, l='MpServer', x=1974.22, y=66.00, z=-2698.38], qa['Zombie'/257034, l='MpServer', x=2084.13, y=37.00, z=-2826.47]]
- Retry Entities: 0 total; []

java.lang.ClassCastException: java.lang.Integer cannot be cast to java.lang.Byte
at lt.a(SourceFile:83)
at qa.h_(SourceFile:97)
at qa.by(SourceFile:61)
at ln.c(SourceFile:1131)
at ps.c(SourceFile:25)
at qa.c(SourceFile:137)
at ln.j_(SourceFile:531)
at ps.j_(SourceFile:30)
at qa.j_(SourceFile:152)
at xe.a(SourceFile:1218)
at xe.g(SourceFile:1197)
at xe.h(SourceFile:1122)
at net.minecraft.client.Minecraft.l(SourceFile:1278)
at net.minecraft.client.Minecraft.J(SourceFile:582)
at net.minecraft.client.Minecraft.run(SourceFile:534)
at java.lang.Thread.run(Unknown Source)
--- END ERROR REPORT 8ba8e66e ----------

Please help,
Joeyyugioh