"That's how the game works right now, it requires more than 2 GB Virtual Address Space as single process and 32bit can't offer that by default but Microsoft made it possible to increase the VAS to 3 GB which will solve the issue in most cases. Maybe the devs find a way bypassing this limitation Microsoft put in place, it's not a issue with the game itself, it's a issue within Windows. 64bit OS offers larger VAS by default and can address more to a single process."
Steam fórumról. Van hozzá trükk, de csak akkor mûködik ha 4Gb ram van a gépben legalább, persze akkor meg minek lenne 32 bites OS. :)