Minecraft Forums

I've installed several mods with minecraft forge and I'm getting crashes when I load up my single player world.
The world loads fine and I can walk around without any problems for about 25-45 seconds then it freezes and I get an error message.
The mods I've installed are:
▲Autoswitcher
▲Optifine
▲Extrabiomes XL
▲Inv Tweaks
▲TF2 Teleporter Mod
The error message I get is:

---- Minecraft Crash Report ----
// This doesn't make any sense!

Time: 11/12/12 10:35 AM
Description: Exception in server tick loop

java.util.ConcurrentModificationException
at java.util.ArrayList$Itr.checkForComodification(Unknown Source)
at java.util.ArrayList$Itr.next(Unknown Source)
at ib.b(PlayerManager.java:71)
at ie.b(WorldServer.java:136)
at net.minecraft.server.MinecraftServer.r(MinecraftServer.java:648)
at net.minecraft.server.MinecraftServer.q(MinecraftServer.java:585)
at bcb.q(IntegratedServer.java:110)
at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:492)
at fp.run(SourceFile:818)

Relevant Details:
- Minecraft Version: 1.4.2
- Operating System: Windows 7 (amd64) version 6.1
- Java Version: 1.7.0_06, Oracle Corporation
- Java VM Version: Java HotSpot™ 64-Bit Server VM (mixed mode), Oracle Corporation
- Memory: 263065400 bytes (250 MB) / 594477056 bytes (566 MB) up to 954466304 bytes (910 MB)
- JVM Flags: 2 total; -Xms512m -Xmx1024m
- AABB Pool Size: 7936 (444416 bytes; 0 MB) allocated, 0 (0 bytes; 0 MB) used
- FML: MCP v7.19 FML v4.2.6.422 Minecraft Forge 6.0.1.341 Optifine OptiFine_1.4.2_HD_B2 8 mods loaded, 8 mods active
mcp [Minecraft Coder Pack] (minecraft.jar) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available->Available
FML [Forge Mod Loader] (coremods) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available->Available
Forge [Minecraft Forge] (coremods) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available->Available
mod_ThebombzenAPI [mod_ThebombzenAPI] (minecraft.jar) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available->Available
mod_AutoSwitch [mod_AutoSwitch] (minecraft.jar) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available->Available
ExtrabiomesXL [ExtrabiomesXL] (ExtrabiomesXL-universal-3.2.0.127.jar) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available->Available
mod_InvTweaks [Inventory Tweaks] (InvTweaks-1.44-1.4.2.zip) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available->Available
pitman-87_TF2_Teleporter [TF2 Teleporter] (TF2_Teleporter_1.4.2a.zip) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available->Available
- Is Modded: Definitely; 'forge,fml'
- Profiler Position: N/A (disabled)
- Vec3 Pool Size: 1674 (93744 bytes; 0 MB) allocated, 0 (0 bytes; 0 MB) used
- Player Count: 1 / 8; [ih['Noob_443'/350, l='New World', x=-118.94, y=68.75, z=-51.03]]
- World New World Entities: 0 total; []
- World New World Players: 0 total; []
- World New World Chunk Stats: ServerChunkCache: 0 Drop: 0
- Type: Integrated Server

Any help/fixes would be greatly appreciated