havent seen this error posted yet, Just added IC2 to my mods, started up, ID resolver changed an ID then crashed, here is the stack trace
Mods loaded: 32
ModLoader 1.2.5
mod_CodeChickenCore 0.5.2
mod_MinecraftForge 3.1.2.94
mod_4096IDs version 1.0.1 for MC 1.2.5
mod_NotEnoughItems 1.2.1
mod_BuildCraftCore 3.1.5
mod_BuildCraftBuilders 3.1.5
mod_BuildCraftEnergy 3.1.5
mod_BuildCraftFactory 3.1.5
mod_BuildCraftTransport 3.1.5
mod_SneakyPipes 0.1.1 (Minecraft 1.2.5, Buildcraft 3.1.5, Forge 3.0.1.75)
mod_LogisticsPipes 0.2.2 (built with Minecraft 1.2.5, Buildcraft 3.1.5, Forge 3.0.1.75)
mod_AdditionalPipes 3.0.9 (Minecraft 1.2.5, Buildcraft 3.1.5, Forge 3.0.1.75)
mod_BuildcraftAPS 0.2.315 (MC1.2.5 F3.1.2+ BC3.1.5)
mod_BuildCraftSilicon 3.1.5
mod_AdditionalBuildcraftObjects 0.9.1-94 (MC 1.2.5, BC 3.1.5)
mod_Forestry 1.4.4.0
mod_BuildCraftZFP (Forestry Package)
mod_IC2 v1.95
mod_CompactSolars 2.1
mod_Railcraft 5.0.3
mod_RedPowerControl 2.0pr5
mod_RedPowerCore 2.0pr5
mod_RedPowerLighting 2.0pr5
mod_RedPowerLogic 2.0pr5
mod_RedPowerMachine 2.0pr5
mod_RedPowerWiring 2.0pr5
mod_RedPowerWorld 2.0pr5
mod_WirelessRedstoneCore 1.2.0
mod_WirelessRedstoneRedPower 1.2.0
mod_WirelessRedstoneAddons 1.2.0
mod_IDResolver 1.2.5 - Update 0
Minecraft has crashed!
----------------------
Minecraft has stopped running because it encountered a problem.
--- BEGIN ERROR REPORT 2467a25e --------
Generated 4/24/12 1:11 PM
Minecraft: Minecraft 1.2.5
OS: Windows 7 (x86) version 6.1
Java: 1.6.0_31, Sun Microsystems Inc.
VM: Java HotSpot(TM) Client VM (mixed mode), Sun Microsystems Inc.
LWJGL: 2.4.2
OpenGL: ATI Mobility Radeon HD 4250 version 3.2.9712 Compatibility Profile Context, ATI Technologies Inc.
java.lang.ArrayIndexOutOfBoundsException: 33945
at ModLoader.initStats(ModLoader.java:923)
at ModLoader.init(ModLoader.java:886)
at ModLoader.addAllRenderers(ModLoader.java:155)
at ahu.<init>(ahu.java:77)
at ahu.<clinit>(ahu.java:8)
at net.minecraft.client.Minecraft.a(Minecraft.java:394)
at net.minecraft.client.Minecraft.run(Minecraft.java:732)
at java.lang.Thread.run(Unknown Source)
--- END ERROR REPORT 1bea0c39 ----------
It might be ID resolver, been having couple other issues with mods and it playing nice recently, but if not ...