Sony VAIO laptop's cursor jumps around as I type.

It's the touchpad driver that's causing it. I suggest that you update the driver. You can search for the driver manually or use RadarSync to save your time.

David

I have had this same issue. I realized one day that the palm of my hand was touching the track pad intermittently. Some of the HP laptops have super sensitive track pads. Mine actually has a button that disables it for typing. let me know, if this helps.

(1) If you are using a laptop for typing text and your cursor is jumping around while you are working with a touch pad then it is a common defect in many Laptops. The solution to this is that you disable the touch pad by pressing down Fn key and selecting the appropriate Function key. You have to use a mouse.
(2) If you are using a desktop and the cursor is jumping then it is a very high probability that you have a virus in your computer. Take a updated virus cleaner/remover and scan/clean your system.

I have had the same problem...The touchpad mouse is incredebly sensitive. What is likely happening, is your wrists are coming into contact with the pad and the sensor interprets it as a click and moving your cursor. My solution was to install a usb mouse (mine was wireless) and disable the touchpad.

The reason this is happening is that as you are typing; you're resting some weight on the thin plastic above the touchpad...which then makes contact and registers a 'click'; thus moving your cursor around.  Or you're brushing your thumb against it when hitting the space key.

Some laptops are more susceptible to this than others.  Some more modern laptops come with a button to turn the touchpad off to solve this very problem.

The only thing you can do about this is to disable the touchpad through the touchpad driver (down by the clock, usually) and use a mouse instead.  Depending on how you use your laptop, this will be more or less inconvenient- if your laptop never leaves the desk; disable the touchpad and use a mouse...no problem.  If you go mobile a lot, you'll have to enable and disable the touchpad all the time.

The other thing you can do is adapt your typing style so you don't put any weight on anything but the key you're pressing.  This is quite difficult and uncomfortable, and is not recommended for long sessions.

It is most likely the touch pad...a way you can tell is if you have a USB mouse, turn off the touch pad and use the USB mouse...go to type and see if it still jumps around.

Yes, you are accidently hitting the touch pad.
Trust me--that is what is happening. Some laptops have VERY sensitive touch pads. If you can disable the touchpad and use a mouse, do it. (that is what I do, as I suffered the very same problem.)
On one customer, I had to actually open the computer and disconnect the pad.
If you can't disable it (many new computers have some sort of switch to disable it, even if it's a combo of the Fn key and one of the special function keys, practice better hand position--raise your seat or lower the laptop to keep your wrists from drooping and getting your thumb near the pad.

maybe its keyboard problem ,some keys on ur keyboard.open a new text document and test all the keys of keyborad if any type more than 1 times when u push u have to clean under that key .

Change the sensitivity to your touchpad. It is common when typing for the palm to brush up against the touchpad and the cursor jumps. Should be an Icon in your control panel to take care of it.

Try control panel and double click the mouse icon then settings you can adjust sensitivity there