Crysis stuttering on ATI 5970

this is the sole reason why i signed up here. because of crysis. it's been days now and i still haven't found a solution. my problem is that crysis stutters on my system no matter what settings i use. i have read dozens of forums and searched tons of times for a solution. ive tried everything, from reformatting my system and installing fresh new drivers. i tried solutions that were posted in the internet ie: disabling all monitoring apps because they mess up crysis or something like that. the thing is, none of them worked. i can play all games fine like dirt 2, batman arkham asylum, mass effect 2, nfs shift. but i always have to switch to windows classic mode theme before doing so because the fps drops really low when i dont do so. my system is windows 7 ultimate 64 bit. core i7 930, rampage II extreme, 2gbx3 gskill tri channel 1600mhz, HIS ATI 5970 overclocked to 900/1300(did this to see if it'll help remove the stuttering in crysis since the stock setting didn't, but it also did not fix the stuttering) ati official 10.3 drivers, corsair hx850. i play crysis on all settings very high with AA set to 8x. i get about 40-60 fps. i have tried every setting possible, high settings no aa, changed the ccc settings to blah blah but nothings just seems to work out. please help. i hope i get the right answer in this forum. and i only play crysis on 1440x900, all the games actually. still saving funds for a 1980x1200 monitor.