Aight, so I thought I'd upgrade to 1.8.1. I installed ModLoader, ModLoaderMP, ModLoaderMP Fix, MCForge 1.1.1, and it all went well. However, after installing IndustrialCraft 2, sound suddenly disappears. Somehow, both sliders for the music and sound volume default to "Off" every time the game is launched, even if the options file was edited before.
The worst part, however, is that trying to adjust either of the sound sliders simply freezes the game.
Note, my .minecraft folder is completely clean. I did not install any other mods except those required by IC2. The game functions just fine with all the mods except IC2 installed.