Excel 2007 : Pivot Table- Dramatic size increase after data delete and refresh

I have a pretty basic pivot table looking at sales data; sales person, customer, products, sales $, volume, margin, unit of measure, etc. Nothing fancy. This data included sales from 2007 through full year 2011, about 3000-4000 lines of data per year. I deleted all 2007 data from the source data, about 3000 lines, and refreshed the pivot table. When I did so, the total file size jumped from about 10M with all data to about 40M after deleting 3000 lines of data and refreshing. I assume this has something to do with the cache, but can't for the life of me figure out how to clean the cache to shrink it. Any direction would be much appreciated.

Paul

Thanks Jeff, and good thought, but no change. The thing I really don't get is that I delete 3000 rows of data and after refreshing the pivot table the files size was 4 times larger, from 10,000kb to 40,000kb.

I also notice that when I Refresh the Pivot table the Calculation status bar at the bottom of the screen seems to go through several long recalculations and then lots or real quick calculations, so fast and so many I can't count. The original table before I deleted the data only went through 2 or 3 relatively short/quick calculations. Is there a way to see all that is being recalculated when it is Refreshed?

Thanks,
Paul

Thanks, I will read through it. As for calculated fields, there are some SUM fields, yes, possibly those are the reason, but still doens't make sense that it jumped so much. Will keep looking!

Paul