Most likely, those cells without gridlines are formatted with a white
background. Background fill covers the grid lines. Select the cells in
question, and choose "No fill" (on the Formatting command bar, click
the icon with the bucket pouring paint).
Cordially,
Chip Pearson
Microsoft Most Valuable Professional
Excel Product Group, 1998 - 2009
Pearson Software Consulting, LLC
www.cpearson.com
(email on web site)
