How to avoid when linked source data is changed, chart turns blan.
 

When I created new charts in Excel 2003, each previous chart became blank.
Therefor I saved the file unter a new name and copied the previous chart to
the new file. This created ofcourse links to the other files.

Now I want to change the source file, but when I do that the chart becomes
blank as well.

Anybody who had this problem before and found out how to solve it ?

Rgds,

Chris