Ok here�s my setup:
My pc:
CPU: Intel core i7 960
GPU: Asus GeForce GTX560 Ti CU2
RAM: 12Gb 1600Mhz
HDD: Samsung Green 500Gb 7200rpm 8mb cache
Motherboard: Asus Sabertooth X58
Windows 7 64bit
All drivers and browsers are up to date.
But as I said previously everything was fine yesterday. And today I installed the new release, opened my project and started working on it and berfore testing it I saved it so now it wont help going back to r78 since it wont run it anymore(tried that already).