Long time ago, when I was seriously preparing a process document on my Laptop and I kept typing in the text as it was flowing from my mind, not looking at the screen. When I looked up to see how it is coming up, surprised that the sentences were scrambled here and there. Then I started observing as to what is happening while typing in and found that the typing position suddenly changes to a an unexpected location, and your key strokes produce characters at an unwanted location! For a while I thought this could be a virus or malware problem or may be a problem with Microsoft Word.
But it did not took much time for me to figure out that this is the 'tap to click' feature of the touch pad. As you keep typing in, your thumb or such other finger taps on the touch pad surface and as a result, the typing position shifts to the position where the mouse cursor was at that time. From then on I have it included in my Laptop build document to have the tap feature disabled. May be this feature is useful for some, but for me it is a hindrance. Similar issues with the pointing stick, which is positioned amidst the keys and if you have it enabled, the chances of you taping on it is even more. Share your experiences with this feature.