Thanks Abel, but the properties of all of these buttons ARE set to not move or size with cells.
Also, this wouldn't explain the case in which the buttons disappeared altogether (in all the worksheets of a workbook) even though Excel seems to think they are all still exactly where they are meant to be (until you try to change any of their properties
when it realises it can't do so).
The notable thing is that, of 5 identically constructed workbooks, all being subjected to the same set of procedures, the disappearing problem only occurred in one and the resizing problem occurred in only one sheet of another, which makes
it all look a bit too random for comfort.
Ben