Sony vaio keyboard problem of simultaneous key press

Hi techies,
I bought a new sony vaio vpcca35fn laptop a few days ago.
I have a problem with its keyboard while pressing multiple keys simultaneously while playing games (fifa 10).
I cannot press 3 or 4 keys simultaneously. Two keys for directions, third key for sprint, & the fourth key for pass/kick.
I tried the key combinations in notepad too, but failed again.
Please, guide me for what can be done to solve this problem.