[Linux] Amnesia: The dark descend (demo) exits after tutorial

[T3STY]

I have successfully installed the demo version of Amnesia: The dark descend and I started playing it. I press play and I can follow the starting steps; when I end the tutorial steps a "Loading" screen appears, but then the game suddenly exits. I'm not sure what happens, I tried any graphics and audio configuration, but nothing changes.
I'm running Fedora 18 x64 with Linux kernel 3.7.5 and my hardware is:
CPU: AMD Phenom II x6 1100T @3.3 GHz
GPU: ATI Radeon HD 4850 (I know, it's very old... could it be the cause?)
RAM: 8GB DDR3, 1333MHz

Does someone have any idea on what's happening?