Keyboard Cursor Jumping (by 4 users)

Hi,
Recently I started having some problems while typing on my Acer laptop....While I'm typing the cursor will sometimes jump back to an sentence above or between letters. I've done a search about this problem and mostly the answers I see are it's caused by accidently touching the touch pad. That's not the case here. I've had this laptop over a yr and the problem only started about 2 weeks ago.
Thanks,
Susan