Here's the structure of the problem table (which usually begins with 'N E W S H E A D L I N E S').
This table is width 100%; two rows; three columns;
The first row: widths 15, 125, 15 ... The second row: widths 15, 100%, 15

| that |

Here's the first row in a table on its own. This table is width 100%; one rows; three columns; This row: widths 15, 125, 15

Here's the second row in a table on its own. This table is width 100%; one rows; three columns; This row: widths 15, 100%, 15

| that |

Note that in Nav4.x, the middle column gets the width of the maximum width cell in the column; on 5.0, the middle column gets the opposite treatment.