I am new to installing forge and i spent about 2 hours researching my error but cant find any solutions: 
I have forge installed and verified, but when i go to single player and create a new world or try and enter an old one then it gives me the following error: 
  
(Yes this is CLIENT forge, Yes it is the latest version and No i did not use an installer, all manual) 
  
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ERROR REPORT: 
---- Minecraft Crash Report ---- 
// Uh... Did I do that? 
  
Time: 12/23/12 1:15 AM 
Description: Exception in server tick loop 
  
java.lang.NoClassDefFoundError: org/bouncycastle/jce/provider/BouncyCastleProvider 
	at bdz.c(IntegratedServer.java:99) 
	at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:458) 
	at fy.run(SourceFile:849) 
Caused by: java.lang.ClassNotFoundException: org.bouncycastle.jce.provider.BouncyCastleProvider 
	at cpw.mods.fml.relauncher.RelaunchClassLoader.findClass(RelaunchClassLoader.java:179) 
	at java.lang.ClassLoader.loadClass(Unknown Source) 
	at java.lang.ClassLoader.loadClass(Unknown Source) 
	... 3 more 
Caused by: java.lang.NullPointerException 
	at org.objectweb.asm.ClassReader.<init>(Unknown Source) 
	at net.minecraftforge.transformers.EventTransformer.transform(EventTransformer.java:29) 
	at cpw.mods.fml.relauncher.RelaunchClassLoader.runTransformers(RelaunchClassLoader.java:222) 
	at cpw.mods.fml.relauncher.RelaunchClassLoader.findClass(RelaunchClassLoader.java:171) 
	... 5 more 
  
  
A detailed walkthrough of the error, its code path and all known details is as follows: 
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-- System Details -- 
Details: 
	Minecraft Version: 1.4.6 
	Operating System: Windows 7 (amd64) version 6.1 
	Java Version: 1.6.0_26, Sun Microsystems Inc. 
	Java VM Version: Java HotSpot 64-Bit Server VM (mixed mode), Sun Microsystems Inc. 
	Memory: 466744872 bytes (445 MB) / 514523136 bytes (490 MB) up to 954466304 bytes (910 MB) 
	JVM Flags: 2 total; -Xms512m -Xmx1024m 
	AABB Pool Size: 0 (0 bytes; 0 MB) allocated, 0 (0 bytes; 0 MB) used 
	Suspicious classes: FML and Forge are installed 
	IntCache: cache: 0, tcache: 0, allocated: 0, tallocated: 0 
	FML: MCP v7.25 FML v4.6.12.511 Minecraft Forge 6.5.0.471 3 mods loaded, 3 mods active 
	mcp [Minecraft Coder Pack] (minecraft.jar) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available 
	FML [Forge Mod Loader] (coremods) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available 
	Forge [Minecraft Forge] (coremods) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available 
	Profiler Position: N/A (disabled) 
	Player Count: 0 / 8; [] 
	Type: Integrated Server (map_client.txt) 
	Is Modded: Definitely; Client brand changed to 'forge,fml' 
  
  
  
  
  
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any help would be much appriciated