it's a dual core issue 100% (as in it uses 100% of both CPU's)
i have:
AMD Athlon64 x2 4200+
Asus nForce4 Ultra
BFG GeForce 7800GTX
2GB OCZ DDR400 Platinum
Creative X-Fi
on my Logitech G15 keyboard, it has a monitor for CPU/RAM, and it montiors each core seperately, and when this game loads, it uses 100% of both CPU's. so it's definately an issue with the dual core, and it seems that a lot of poorly written games cannot support modern systems. i have no issues with newer games such as Civ4, WoW, AoE3, or Dungeon Siege II.
plus the game doesn't support widescreen, which is a shame, all 3D non-sprite games should support various resolutions, such as 1920x1200 (my default).