my technic pack keeps crashing

[slimsanta33]

--- BEGIN ERROR REPORT 58b32eb6 --------

Generated 6/26/12 3:08 PM

Minecraft: Minecraft 1.2.5

OS: Mac OS X (i386) version 10.6.8

Java: 1.6.0_29, Apple Inc.

VM: Java HotSpot Client VM (mixed mode), Apple Inc.

LWJGL: 2.4.2

OpenGL: ATI Radeon X1600 OpenGL Engine version 2.0 ATI-1.6.36, ATI Technologies Inc.

java.lang.IllegalArgumentException: Slot 169 is already occupied by buildcraft.silicon.BlockLaser@16e32d7 when adding buildcraft.factory.BlockAutoWorkbench@1cbc824

at pb.<init>(Block.java:251)

at agy.<init>(BlockContainer.java:7)

at buildcraft.factory.BlockAutoWorkbench.<init>(BlockAutoWorkbench.java:33)

at BuildCraftFactory.initialize(BuildCraftFactory.java:100)

at mod_BuildCraftFactory.modsLoaded(mod_BuildCraftFactory.java:36)

at cpw.mods.fml.common.modloader.ModLoaderModContainer.postInit(ModLoaderModContainer.java:330)

at cpw.mods.fml.common.Loader.postModInit(Loader.java:280)

at cpw.mods.fml.common.Loader.initializeMods(Loader.java:605)

at cpw.mods.fml.client.FMLClientHandler.onLoadComplete(FMLClientHandler.java:203)

at net.minecraft.client.Minecraft.a(Minecraft.java:426)

at net.minecraft.client.Minecraft.run(Minecraft.java:735)

at java.lang.Thread.run(Thread.java:680)

--- END ERROR REPORT 1a8af051 ----------