Hello, I′ve started playing yesterday and I′m unable to complete the first mission, Unbound.

When the dragon starts attacking and you have to escape from it, later you have to follow Hadvar to Helgen Keep. But when we reach the open area where he should encounter with Ralof, and you have to decide which one to follow, Ralof never appears and Hadvar just stops where he should have confronted him.
At that moment, If I try to save, the game hangs while saving and I have to kill the game. If I enter the keep the screen fades to black, only showing my level on the upper right part, and stays there doing nothing.

I′ve reinstalled the game about 4 times, changed every setting in the Launcher/Ini file. I′ve started the game about 20 times already and only ONCE, that damned Ralof appeared, but since I was quicktesting and dind′t customize my character, I started a new game thinking I finally fixed it.. but no, still happens, and no idea what I made different on that run.

My specs:
Windows 7, Dual Core E8400, 3Gb Ram, ATI HD6870 with latest 11.10 drivers, Creative X-FI Gamer soundcard. Nothing overclocked.