Just as a test, what happens if you drop the detail level down to minimum settings?
I'm not really up on the latest in PC gaming, but I think the other games you mentioned came out considerably before the one you're having difficulties with, so it's not necessarily out of the question that the older games would work fine,while the newer one does not.
i recently purchased COD MW3 for pc on my new rig. it's running like utter crap. this machine features an AMD FX-6200 6-core processor at 3.8ghz, an Sapphire Radeon HD 6950 2gb DDR5 graphics card, and 8gb ddr3 ram. i play battlefield 3 on high settings, skyrim completely maxed, and every other heavy game and application i have performs wondefully. what struck me as strange, is that while i was playing mw3, standing in the corner of a map facing out of the map, FRAPS was telling me i was getting over 160 fps, and it would run great. but as soon as i turn around, my game would just crap itself basically, and my frames would drop to 16. i've checked out the possibility of driver issues, but that wasn't the case. could this be some kind of rendering issue?