WotLK Blackscreen when starting the game.

[x123p]

Just downloaded the "old" wrath of the lichking client via utorrent and started it after. But all i get is just a black screen where i hear the sound for like 2-3 seconds and than it disppears. It also happens sometimes that i just get back to my destop while i can hear the sound from the intro movie. Also if i click on my black screen i get back to my destop. Really weird actually. No idea wheres the problem and i hope someone can help me :)

Thanks in advance

Fixed. The downloaded config file was just broken. replaced it with a config file from a friend. Now it works.