Black screen with a gray line

I downloaded, extracted and ran the game for the first time.
It connects to the server, but the game screen is black with a gray line or two.

I am on windows Vista,

This doesn't sound like the "normal" black out upon entering the game fo rthe first time.

Are you able to see anything at all other than the black screen and grey line?
If not then it is probably a compatability mode issue. What is your video setup?

Have you tried running the game in XP compatibility mode?

Right click on the exe file
Select Properties
Select the Compatability tab
Tick the Run this program in compatability mode
Select Windows XP

That may help.