Need help

Minecraft has crashed! ---------------------- You need to follow these steps:1. Work out which mod is the cause of your problem. Is there something in the log below that points to a certain mod? If you recently installed a new mod then it is likely the cause of this problem2. Google for the mod authors forum.3. Read the First Post and the last 3 pages of the thread and see if other people are reporting similar issues4. Post the following Error Report in the forum.--- BEGIN ERROR REPORT ---Generated 18.04.12 21:12Minecraft: Minecraft 1.1OS: Windows 7 (x86) version 6.1Java: 1.6.0_31, Sun Microsystems Inc.VM: Java HotSpot™ Client VM (mixed mode), Sun Microsystems Inc.LWJGL: 2.4.2[failed to get system properties (java.lang.NullPointerException)]--- ModLoader 1.1 ---Mods loaded: 71mod_MinecraftForge 1.4.1.58mod_Timber 1.2.3mod_InvTweaks 1.40 (1.2.3)mod_Railcraft 4.1.4mod_RedPowerArray 2.0pr4emod_RedPowerCore 2.0pr4emod_RedPowerMachine 2.0pr4e--- End Modloader ---java.lang.ExceptionInInitializerError at net.minecraft.client.Minecraft.a(Minecraft.java:309) at net.minecraft.client.Minecraft.run(Minecraft.java:691) at java.lang.Thread.run(Unknown Source)Caused by: java.lang.RuntimeException: java.lang.NullPointerException at ModLoader.init(ModLoader.java:917) at ModLoader.addAllRenderers(ModLoader.java:186) at aho.(aho.java:79) at aho.(aho.java:9) ... 3 moreCaused by: java.lang.NullPointerException at org.lwjgl.opengl.GL11.glGenTextures(GL11.java:1373) at et.a(SourceFile:22) at aar.b(RenderEngine.java:211) at forge.MinecraftForgeClient.preloadTexture(MinecraftForgeClient.java:69) at mod_Railcraft.load(mod_Railcraft.java:56) at ModLoader.init(ModLoader.java:890) ... 6 more--- END ERROR REPORT ---