I've recently reinstalled Crysis 2 after finally getting my hands on a DX11-capable card (well, two of 'em) and I'm restarting the game from scratch but as soon as I get to the section where the sub has been attacked and I take control of my character to swim through the sub, the game CTD's - the game is visible in the taskbar and I still hear background sounds but the game will not return to full-screen or do anything when I clikc the taskbar button to bring the game back up.
I need to press Ctrl, Alt, + Del to force quit the game

My specs are:
Win7 x64 SP1 w/ all updates
Intel i7 920 oc'd to 3.5Ghz per core
6GB of DDR3 1600Mhz RAM
2x Gigabyte GTX560 Ti SuperOverClock cards with 1GB mem each
I'm using nVidia Forceware 280.26.
Am I to assume I should turn of DX11/Hi-Res textures to see if that allows me to progress?
Anything else I could try?