Hey! I've been playing the Aether II for a while now, and have been getting freezes and then it won't respond. Once I tried updating my drivers, and that helped for a while. This is also with vanilla. I tried allocating 4GB, but that only helped vanilla Minecraft, for the Aether launcher doesn't have an option to quickly allocate ram. I am also using Natua 1.6.4, And chocolate quest / Better dungeons.
Modded client 1.6.4 Freezing every 1 - 10 minutes!