Invisible textures
 

I've just purchased the steam version of the game, and all the unit textures are invisible!!! I (try to) play on a MacBook Pro, with OSX v. 10.8.2.

Have I wasted my money? As I've seen someone posted the same question a couple of months ago. What a terrible support ...

Hey guys, i need your help about a problem: I've reached castle Orinoko, but there is an enemy unit that is stuck and does not move. I cannot attack it and it doesn't attack me either. I need to kill it to be able to go in the castle.
What should I do?

Please help! :)