I just signed up to report a graphical error that matches PlatinumSkullz's error report, except using Magic Launcher I was able to search through the logs and found this:
Display Spoiler
Class not present: LightCache
Allocated subtessellator, count: 1
Warning: Texture /ic2/sprites/block_advmachine.png not preloaded, will cause render glitches!
Warning: Texture /ic2/sprites/block_advmachine.png not preloaded, will cause render glitches!
setupTexture: "/ic2/sprites/block_advmachine.png", id: 1067
Its the only graphical error of its kind present in the entire log, and it messes with everything from the Ironchest mod to a world-gen volcano from RedPower2, and my character model and causes missing limbs and other graphical glitching with mobs and other blocks that won't render correctly. Any help would be awesome.