In a Monthly Data Entry Form the header text wraps when the text does not fit in the width of the cell.  The text will typically break up the text by spaces, however certain fonts wrap at the width of the column instead of the space.  The Header font is set in the Monthly Data Entry Options form.  Example:

Font is set to Cambria 10pt Bold:

Change font to Arial 10pt Bold:

To wrap properly use one of the following fonts:

Arial
Century Gothic
Comic Sans
Courier
Courier New
Fixed System
Franklin Gothic
Garamond
Garamond
Georgia
Impact
Lucida Console
Lucida Sans Unicode
Modern
MS Reference Sans
MS Sans Serif
Palatino Linotype
Tahoma
Times New Roman
Trebuchet MS
Veranda

The following fonts do NOT wrap properly:

Calibri
Cambria
Candara
Century
Consolas
Constantia
Corbel
Gabriola