Excel 2007 hangs while loading chart
 

I have a sheet with 20000 rows and 5 columns of data with just 2 simple
calculations in each row.
On a separate sheet is a chart that gets its data from the spreadsheet.
Whenever I change some data oin the spreadsheet and click on the chart's
tab, the program "hangs" for some 4 minutes. In XL 2003 it didn't do that.

Any idea what is going on? Thanks.

Gerry