When creating underlines in ClarisWorks 5.0, selecting 'Underline' in the Styles menu and then using the space bar to place the line in your document has been found to not print the line created. The problem also occurs when documents created in older versions of ClarisWorks are used in ClarisWorks 5.0. Lines created by either option spaces or tab spaces will print. As of yet, there is no solution to correct the problem.
It is recommended that you not create underlines in this fashion. The best way to make long underlines is by creating a tab and setting the tab to have a fill of the underline character. This can be done by double clicking on the tab after it is created. You could also create a plain tab and use the drawing tool to draw in a line as well.