Maybe you added new data to the source table, and those rows aren't
included in the pivot table's source. To check:
Right-click on a cell in the pivot table
Click on PivotTable Wizard
Click Back, and make sure all the rows are included in the source range
Click Finish
If data will be added to the source table, you can create a dynamic
range, and base the pivot table on that, as described here:
http://www.contextures.com/xlPivot01.html
