Hello. I know i posted about flan's mods earlier, but now i am needing some help with the Aether mod for 1.0.0

My brother had been begging me to install it and won't shut up so i tried to install it but it came up with this error:

Mods loaded: 5
ModLoader 1.0.0
mod_Aether MC 1.0.0 Version 1.04
mod_ModLoaderMp 1.0.0
mod_SAPI r11
mod_Trivia MC 1.0.0 Aether Edition

Minecraft has crashed!
----------------------

Minecraft has stopped running because it encountered a problem.

If you wish to report this, please copy this entire text and email it to support@mojang.com.
Please include a description of what you did when the error occured.

--- BEGIN ERROR REPORT a5a55731 --------
Generated 5/6/12 11:41 AM

Minecraft: Minecraft 1.0.0
OS: Windows 7 (amd64) version 6.1
Java: 1.6.0_29, Sun Microsystems Inc.
VM: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Sun Microsystems Inc.
LWJGL: 2.4.2
OpenGL: Intel(R) HD Graphics version 2.1.0 - Build 8.15.10.2189, Intel

java.lang.VerifyError: (class: mod_Weather, method: moveToEnt signature: (Lacq;Lacq;FZ)V) Incompatible argument to function
at java.lang.Class.getDeclaredFields0(Native Method)
at java.lang.Class.privateGetDeclaredFields(Unknown Source)
at java.lang.Class.privateGetPublicFields(Unknown Source)
at java.lang.Class.getFields(Unknown Source)
at ModLoader.setupProperties(ModLoader.java:1679)
at ModLoader.addMod(ModLoader.java:264)
at ModLoader.readFromModFolder(ModLoader.java:1272)
at ModLoader.init(ModLoader.java:734)
at ModLoader.AddAllRenderers(ModLoader.java:162)
at wb.<init>(RenderManager.java:104)
at wb.<clinit>(RenderManager.java:42)
at net.minecraft.client.Minecraft.a(Minecraft.java:314)
at net.minecraft.client.Minecraft.run(Minecraft.java:613)
at java.lang.Thread.run(Unknown Source)
--- END ERROR REPORT 505b6b19 ----------

If anyone could help me, that would be great. My minecraft.jar has no other mods installed