I'm having problems with my laptop. The keyboard is being generally unresponsive. Mainly when I type the letters will jump to a different part of the screen and continue the sentence from there making it impossible to type without having to constantly go back and retype.
I don't know if it has anything to do with it but the Num Lk seems to be working in reverse too.
The problem you describe is probably not your keyboard. It will be related to your touchpad. When typing on you laptop keyboard you are brushing the touchpad with your hand and moving the pointer to a different location on screen. When you continue to type the text appears where the pointer/cursor has moved to.
Try reducing the sensitivity of your touchpad, by using the application. Im guessing its a synaptics touchpad. If the laptop is using the default windows driver, this makes the touchpad too sensitive. You will have to download the appropriate software driver for it.