For years I've used nested pivot tables - multiple tables stacked vertically, drawing data from separate worksheets, the entire stack forming the source of other pivot tables.

I have such a stack in a new workbook. It is accessed by a pivot table in another worksheet of the same workbook. A pivot table derived from that source, together with several adjacent columns derived from it, is the source of another pivot table. This in turn, with associated columns, becomes the source of a third PT, which likewise becomes the source of a fourth. The end result is a table of donors to my charity, separated into categories (Platinum, Gold, etc.) and sorted alphabetically within category. The same process is repeated with data from a pivot table sourced by data in another workbook.

All was going well until Refreshall began causing long delays ("Excel not responding"), though individual tables would refresh quickly. If I found a table that was slow to refresh I deleted and replaced it, but the problem is only getting worse. Now if I make any change to the worksheet - a single cell not associated with a pivot table - Excel goes into "Not Responding" for many minutes.

This is very frustrating, as the worksheet does what I want but the delays make it unworkable. Could they be due to the PT inter-dependencies? If so, how do I overcome them? They do not entail circularity.