We have a toolbar we create in code, so that it can be customized on a
worksheet-by-worksheet basis. When a sheet is opened, by clicking on the
tabs, the code examines the toolbar, removes any existing buttons, and
replaces them with the correct ones for that sheet.

When this code first runs, it is extremely fast. The entire process of
deleting the existing buttons, looping over a list to see which ones are
needed, and then adding them back takes well under a second. However, this
process slows down. Today it is taking about 4-5 seconds to do the same
thing. There have been no data changes at all.

The "solution" so far is to use the Toolbars... editor to delete the toolbar
and let the code re-draw it from scratch. This works for a day or two before
it slows down again.

Does anyone know what's going on, and how to fix it?

Maury