I have installed the most recent versions of Forge and the mods I am trying to use (buildcraft and divine rpg), but Minecraft crashes while trying to load (after the Mojang screen).   
It says "java.lang.IllegalArgumentException: Slot 4095 is already occupied by buildcraft.energy.BlockOilStill@6c21f22f when adding xolova.blued00r.divinerpg.blocks.BlockXolovonStone@28a3231f."  Is there anything I could do to fix this problem? 
  
  
Here's the crash report: 
  
  
  
Thanks in advance!