Cursor position jumps back or down a line or two...

Question

All too often when I am typing an email message in Microsoft Outlook on my Dell Precision M6300, the cursor position jumps back a position or down a line or two, inserting itself out of position. I then bring it back to where it belongs using the arrow keys. I can find no correlation between my keystrokes and when this happens. My wife has noticed the same thing on her Dell laptop. It never happened on my old desktop PC. Any explanation or suggestions?