The layout has mistakenly been set to display in two or more columns while the width of the column (the white area of the layout) has been made too wide to fit the number of columns selected within the printable area of the page. This results in groups of records (specifically, those which would fall in the columns which are off the right side of the page) not printing. To remedy the situation, click
Layout Setup in the
layout bar, and set the number of columns to the desired amount. Then, if necessary, adjust the right margin of the column by clicking and dragging the vertical dashed line on the layout.