Uncontrollable cursor

I'm finding it very hard to work the cursor while playing this demo. It slides all over and makes it difficult to aim. I'm on a borrowed laptop so maybe it's a computer problem. I'd like to buy the game today, but before I do would like to know whether anyone else has had this problem. I'm due to get my own computer back from repair tomorrow.

I've had this problem sometimes with this type of games. I'm on a laptop and ususally it is because the touchpad or my finger is dirty. I just got done playing some Luxor 3 and did not have any problem today.

Thanks! I'm going to assume the problem's with this laptop, and will buy the game.