I recently migrated three workbooks from excel 2003 - 2007.

The problem I describe does not happen in 2003.
There were no errors when converting the files.

Charts.xlsx references chart data from two sources, sourceOne.xlsx and
sourceTwo.xlsx.

Now when ALL THREE workbooks are open, the charts display (as they should)
the proper 'major units' (which is monthly) so for a series of 365 days,
there twelve x-axis dates presented.

However, when I close the source workbooks, the charts ignore the 'Major
Units' and return to displaying a label for every day in the data (365
labels).

This is not only not readable but also makes the 20 or so charts on the page
load extremely slowly.

Has anyone run into this and figured out a way to fix it?

Thanks!