Hi, I have been following this forum but some time, but now i need some help myself. I have a rMBP 2.6/16/512, about a month old, which im very happy with. However today the machine has suddenly started freezing with the Intel HD 4000 card active. If i turn off automatic graphics switching, forcing the computer to use the 650 Nvidia card everything works, but as soon as this is turned on, the system switches back to the HD 4000 and if the card is pushed just a little, fx by opening safari og mission control, the computer freezes. I can still move the mouse, but the rest is stuck in the mission control animation. Only solution is to hold down power button. I have contacted Apple support and clean installed ML, but neither helped. I plan to bring the computer to the local premium apple reseller tomorrow, but in the meantime, does any of you guys have any ideas or suggestions? Thanks in advance.