Total revamp of this review, seems the problem with this game and the rest of the Agri Sim series is their reliance on some of the earliest PhysX technology. If your copy's working after installing nvidia's legacy physx drivers, and you update the video card drivers later on, you will need to reinstall the legacy physx package after the video card driver update, since something in it gets busted.
Note here, if you have one of Ati/AMD's latest video cards, NONE of these games, nor others that require the legacy PhysX pack (original Two Worlds, Darkest of Days) , will likely EVER work for you. Nvidia's too cheap to provide an install for you guys, unfortunately.
Now, as for Ag Sim 2011, believe it or not...I do recommend it. If you avoid hiring AI workers, and keep all your equipment parked outside (even the biggest garage cannot hold much), the game works just fine. Yes, it's a resource-hog, but you can play with the lag on slightly older machines like mine. I've never once had equipment fall through the ground, and the multiplayer still works. Wait for a sale, though - this needed a patch badly, so the heck with giving UIG more money than necessary. ;D