Printing Issues While Using Courier New Font

We are having problems while printing to our network printer - HP 9050 (PCL 6 driver) using the Courier New font from Office 2007.  We are using the Windows 7 operating system on various workstations on our office network.  Certain cells in Excel are printing in a lighter shade than the rest of the page - there seems to be a pattern to the light vs. dark shading.  If a cell with text is truncated due to inadequate column width the cell prints lighter.  Lines with cells that have been underlined are also printing in a lighter shade.  When we change the font size under the "normal style" in excel to match the font size being used on the page the rows with underlined cells print consistently with the rest of the page.  In this case the only cells printing with the lighter shade are those that are truncating. When I change the font to Times New Roman or Calibri the entire page prints with a consistent shade. Are there any known problems with the Courier New font when printing using the hardware and software noted above. Could you please provide any information that you can to confirm or disprove that this is a font problem vs. a printer problem? Thank you, Gisele L. MacDonald