Minecraft mod miért írja ki ez az üzenetet?

sziasztok az lenne a kérdésem hogy itt mi a baj? :

--- BEGIN ERROR REPORT c947ea3e --------

Generated 2012.08.18. 14:05

- Minecraft Version: 1.3.1

- Operating System: Windows 7 (amd64) version 6.1

- Java Version: 1.6.0_33, Sun Microsystems Inc.

- Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Sun Microsystems Inc.

- Memory: 417373576 bytes (398 MB) / 514523136 bytes (490 MB) up to 954466304 bytes (910 MB)

- JVM Flags: 2 total; -Xms512m -Xmx1024m

- ModLoader: Mods loaded: 2

ModLoader 1.3.1

mod_PCmobile 3.4.9x

java.lang.VerifyError: (class: mod_PCtransport, method: registerItems signature: ()V) Incompatible argument to function

at java.lang.Class.getDeclaredFields0(Native Method)

at java.lang.Class.privateGetDeclaredFields(Unknown Source)

at java.lang.Class.getDeclaredFields(Unknown Source)

at ModLoader.setupProperties(ModLoader.java:2048)

at ModLoader.addMod(ModLoader.java:326)

at ModLoader.readFromModFolder(ModLoader.java:1413)

at ModLoader.init(ModLoader.java:916)

at ModLoader.addAllRenderers(ModLoader.java:169)

at avx.<init>(RenderManager.java:86)

at avx.<clinit>(RenderManager.java:12)

at net.minecraft.client.Minecraft.a(Minecraft.java:425)

at net.minecraft.client.Minecraft.run(Minecraft.java:769)

at java.lang.Thread.run(Unknown Source)

--- END ERROR REPORT cab608f6 ----------