I tried playing offline, but the game demonstrates the same behavior.
However, I think I have managed to prevent the game from crashing by tweaking down the display resolution and the visual effects. With the following configuration, I have yet to experience an other crash (just finished a 2hours playing session ):
"Sans" is french word roughly meaning "Feature is off"
DirectX11 is enabled, and the resolution is 1600*900 (down from 1920*1080)
My computer specs:
Intel Core i5 760 @ 2.8Ghz
8GB RAM DDR3
Gigabyte NVIDIA GeForce GTX 560 Ti 1 Go (with latest beta driver)
Windows 7 Ultimate 64bits
Since it now works, I won't try an other cache integrity check: "If it ain't broken, don't fix it"