Is this happening when you are typing on a laptop or a desktop computer? If on a laptop, it is usually the touch pad which your palm ends up hitting which puts the cursor somewhere different on the page. You just need to set the proper setting for your touchpad to not respond when you're typing or, if it doesn't have that setting, to set it so that clicks are not recognized from the touchpad.
Bob, thanks. It is on a laptop, and since you brought that to light, there is a good chance that is what is happing, as often I have caught myself missing the space bar. Since my neck/disc operations my fingers don't go where I want them to go.
No, not really. You can disable it by use of the mouse settings in Control Panel if the driver for the trackpad is installed for that brand of trackpad. But the main thing for this type of problem is just to disable the tap for clicking with the trackpad and that is done using the mouse settings as long as the trackpad driver is installed.