Charts not visible
 

Excel 2007 - I have Chart sheets that are hidden until you execute a macro,
which opens up (hidden rows in diff worksheet in workbook) the data source
and unhides the sheet. I know if I open the chart without unhiding the rows,
the chart is not visible but I have checked and the rows are visible. this
used to work perfectly but now the charts will not show - just the blank
chart sheet background??
Seems to be a security issue but I cannot find anything. Again used to work
perfectly...
I didn't change anything that I know of....