hello my game crashes on startup when i make a world or load one

---- Minecraft Crash Report ----
// Sorry :(

Time: 28-12-12 11:13
Description: Exception in server tick loop

java.lang.VerifyError: (class: ir, method: d signature: (III)Z) Incompatible argument to function
at gm.a(ServerConfigurationManager.java:317)
at bec.b(IntegratedServerListenThread.java:90)
at net.minecraft.server.MinecraftServer.r(MinecraftServer.java:702)
at net.minecraft.server.MinecraftServer.q(MinecraftServer.java:598)
at bdz.q(IntegratedServer.java:123)
at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:497)
at fy.run(SourceFile:849)

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

-- System Details --
Details:
Minecraft Version: 1.4.6
Operating System: Windows 7 (amd64) version 6.1
Java Version: 1.7.0_10, Oracle Corporation
Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
Memory: 408275600 bytes (389 MB) / 648740864 bytes (618 MB) up to 1908932608 bytes (1820 MB)
JVM Flags: 2 total; -Xms512m -Xmx2048m
AABB Pool Size: 2202 (123312 bytes; 0 MB) allocated, 2202 (123312 bytes; 0 MB) used
Suspicious classes: FML and Forge are installed
IntCache: cache: 0, tcache: 0, allocated: 3, tallocated: 63
FML: MCP v7.25 FML v4.6.17.515 Minecraft Forge 6.5.0.489 4 mods loaded, 4 mods active
mcp Minecraft Coder Pack Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available->Available
FML Forge Mod Loader Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available->Available
Forge Minecraft Forge Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available->Available
TreeCapitator TreeCapitator Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available->Available
Profiler Position: N/A (disabled)
Vec3 Pool Size: 334 (18704 bytes; 0 MB) allocated, 334 (18704 bytes; 0 MB) used
Player Count: 0 / 8; []
Type: Integrated Server (map_client.txt)
Is Modded: Definitely; Client brand changed to 'forge,fml'