Add rest to TAB ?

I found how to do it, in the handbook, but it wont work on my Mac. It just leaves a blank space. I'm using the semicolon to input the rest.

NOTE: I am typing up just a TAB, no score. Perhaps that is the problem?

Here follows what the handbook says:

To enter notes into tablature from the computer keyboard:

First, ensure that you are not in note-input mode. Select the measure or existing note from which you want to begin note entry.
Switch to note input mode (N): a short 'blue rectangle' appears around one tablature string: this is the current string.
Select the duration of the note or rest that you wish to enter (see below).
Press the up/down arrow keys to move the cursor to the desired string. Use the left/right arrow keys to navigate through the score.
Press 0 to 9 to enter a fret mark from 0 to 9 on the current string; to enter numbers with several digits press each digit in sequence. Keys A to K (skipping I) can also be used: convenient when working in French tablature. For L , M, N, use the alphanumeric keyboard and type respectively 10, 11, 12.

Note: You cannot enter a number higher than the "Number of frets" value set in the Edit String Data dialog.

Press ; (semicolon) to enter a rest of the selected duration.

So I get to the input of the semicolon but that just moves the blue box one step to the right. If I type a "0" instead of the ";" I get an open string code of "0" on the string I'm on.