Minecraft crash after IC2 installation. Help!

  • Yeah, just downloaded the latest version of IC2 (industrialcraft-2-client_1.81.jar), but after I put it in the 'mods' folder minecraft crashed when loading, giving me this message (yes, I've got all the latest modloaders, etc.):

    Mods loaded: 17
    ModLoader 1.2.3
    mod_ModLoaderMp 1.2.3v3
    mod_BuildCraftCore 2.2.13
    mod_BuildCraftBuilders 2.2.13
    mod_BuildCraftEnergy 2.2.13
    mod_BuildCraftFactory 2.2.13
    mod_BuildCraftTransport 2.2.13
    mod_IC2 v1.81
    mod_RedPowerArray 2.0pr4e
    mod_RedPowerCore 2.0pr4e
    mod_RedPowerLighting 2.0pr4e
    mod_RedPowerLogic 2.0pr4e
    mod_RedPowerMachine 2.0pr4e
    mod_RedPowerWiring 2.0pr4e
    mod_RedPowerWorld 2.0pr4e

    Minecraft has crashed!

    Minecraft has stopped running because it encountered a problem.

    --- BEGIN ERROR REPORT 33904a1f --------
    Generated 22/03/12 23:58

    Minecraft: Minecraft 1.2.3
    OS: Windows XP (x86) version 5.1
    Java: 1.6.0_24, Sun Microsystems Inc.
    VM: Java HotSpot(TM) Client VM (mixed mode), Sun Microsystems Inc.
    LWJGL: 2.4.2
    OpenGL: GeForce 9600 GT/PCI/SSE2 version 3.0.0, NVIDIA Corporation

    java.lang.RuntimeException: RedPowerCore: BlockID 250 occupied by ic2.common.BlockMachine, autoAssign is disabled.
    at forge.MinecraftForge.killMinecraft(MinecraftForge.java:422)
    at eloraam.core.Config.getBlockID(Config.java:114)
    at RedPowerMachine.initialize(RedPowerMachine.java:136)
    at mod_RedPowerMachine.initialize(mod_RedPowerMachine.java:61)
    at mod_RedPowerMachine.modsLoaded(mod_RedPowerMachine.java:28)
    at ModLoader.init(ModLoader.java:898)
    at ModLoader.addAllRenderers(ModLoader.java:186)
    at aho.(aho.java:79)
    at aho.(aho.java:9)
    at net.minecraft.client.Minecraft.a(Minecraft.java:395)
    at net.minecraft.client.Minecraft.run(Minecraft.java:732)
    at java.lang.Thread.run(Unknown Source)
    --- END ERROR REPORT 5dc96c31 ----------

    Any Ideas?

    I have buildcraft, redpower and equivilent exchange installed (all for 1.2.3), but they're not causing the crash.</init>
    I have not updated minecraft to 1.2.4 (still 1.2.3).