Your typing may be directed to the wrong place. This can happen if you swap back and forth from one program window to another, or the browser decides to set the focus in the wrong place.
To overcome the problem, click the mouse over the region you should be typing into and then start typing.
For screens where the program displays a line of text which you should type, the typing region is directly below the line of text.
For screens where the program displays a large keyboard and highlights a key which you should type, just click anywhere on the large keyboard before starting to type.
