Here is my system specs:
Asus P8Z77-V DeLuxe MB
Intel i7 3770 3.4 CPU
8GB Kinston DDR3 RAM
EVGA GTX680 2048M GDDR5 RAM
CPU water cooling.

My problem is that I tried playing on the default settings for my system of VERY HIGH but got terrible stutter and then the game totally hung up. I reduced all the settings to LOW but I can only play for about 3 seconds and then it hangs for 3 or 4 seconds and then stutters and then back to play for 3 seconds yada yada yada. I know that Crysis games have always had a demanding system but come on -- mine is just fine and I should be able to play on VERY HIGH. I have the latest video driver from EVGA.
Can any one help please
Thanks
Alan

Does no one have any suggestions?

Check out some posts on here - lots of people having similar issues, its looking like optimisation issues with the game and / or drivers at the moment, some have it worse than others - yours sounds a particularly bad case, personally I dont have it too bad at all its certainly affecting some setups more than others - what have you tried so far apart from altering details?