pivot table % of total column rounding issue

Hello,

When using a "% of total column" in a pivot table I get the percentage values displayed to 2 decimal places whereas the percentages are actually stored to 13 decimal places. This causes percentage totals and subtotals to sum incorrectly so that I routinely have 0.1 errors in the summed percentage totals and subtotals.

Is there a way around this? Thanks in advance,

Mark