Keyboard Typing Problem

Hi there,

I am repairing a macbook for a friend and i am hoping somene here can help me. When typing on the macbook, certain keys when pressed will produce an extra letter, for instance when i press the "m" key it does a "v" as well so pressing m comes out as mv. It also does this when pressing the "r" key, it produces "ru". I dont know wether this could simply mean the keyboard needs replaced, or maybe a software problem that can be easily sorted. Has anyone else ever had this sort of problem?

Thanks in advance!