In addition to checking 'Preserve formatting', you should remove the
check mark from 'AutoFormat table'
Depending on your version of Excel, you may also have to enable
selection (From the Pivot toolbar, choose PivotTable>Select, and click
on Enable Selection)
Other things to try -- if they don't work, you could record a macro as
you refresh and reformat the pivot table. Then, run that when you want
to update.
--Instead of selecting the cells to format the numbers, right-click the
field button, and choose Field Settings. Click Number, and choose your
formatting options there.
--Before formatting cells, use the selection feature to cells. For
example, move the pointer to the top of a column in the pivot table
(just above the column's heading cell). When the black arrow appears
(like the one that appears when the pointer is over a column button),
click to select the column in the pivot table. Then apply the formatting.
