1. did your montier come with any drivers in the first place.
2. have you tried switching connection to a regular VGA connection, if you do not have one in the back of the laptop try and adapter i know that with alot of graphics cards such addapters come free,
3. have you looked at the settings menu under properties when you right click on your background, maybe the coloursetting is set low,
4. you say you are using a laptop , when you connect this moniter is the laptop pluged into the mains ( i dont think it will make too much difference it sounds more like a driver thing to me) because ATI uses power play on most laptops which restrics the power usage of the graphics card, this might confilct with the screen
try pluging the laptop to the mains if you havnt done already, and see if you can switch cabels you never know, but if there is a driver which came with the moniter try installing it. iff not is there anykind of part number anywhere on the moniter? you could try googeling that for driver downloads, or known issues.
Im sorry if this post doesnt solve anything but if anything else comes up or you can think of anymore details please post them.
(bear in mind im writting this at 1:30 in the morning and im pooped