Hi. 
  
I just updated my minecraft to 1.4.6 And installed forge and Extrabiomes XL all latest versions. And when I start the game, it crashes. if I have nothing in .minecraft/mods it works just fine. And I got this error with any mod that goes into .minecraft/mods Details below.  
  
ForgeModLoader-client-0: 
  
  
  
Mod Links: 
 
http://www.minecraftforum.net/topic/1090288-extrabiomesxl-370a-supports-146/ 
http://adf.ly/673885/http://files.minecraftforge.net/minecraftforge/minecraftforge-universal-latest.zip 
 
  
System Details: 
OS: Windows 7 Ultimate 64 Bit 
Processor: AMD Phenom II 4x 965 3.40 GHz 
RAM: 8GB DDR3 Kingstone 
GPU: AMD Radeon HD 6800 Series, 2GB DDR5 RAM, 256 BIT 
Java: Java7 Update 9 
Java: Java7 64-Bit