In auto fill mode, when typing at the end of a line, and there exists text on the following line, occaisionally you will type a space, the word you just typed will move to the next line, but the cursor will remain on the current line. For example: A b c d e f<cursor> 1 2 3 4 5 Typing "g<sp>": A b c d e f <cursor> g1 2 3 4 5