The game acts like its rendering five different worlds at once and can't choose between them. My game will flash different biomes in weird patterns, for ex: If i stand still my game will flash for a bit but then it stops. ill just see repeating patterns of trees. but if i move/look everything will start flashing again changing patterns at like a million times per sec with different blocks and different patterns. Upon writing this i have come upon a sort of fix, i updated to java 8 and all seems to be in working order. if this happens again ill let you know.
Environment
Intel(R) Core(TM) i7 CPU 920 @ 2.67GHz 2.7GHz
4.00 GB RAM
64-bit Windows Vista Operating System
Java 7
Broken AMD drivers. See MC-62958