I encounter this problem in only one of my worksheets. Others are fine.

When I select the upper left data cell (a formatted date cell) the sort
does not recognize the header row 1, even though the sort window is set
to recognize a header row. The 3 options for the sort order hierachy
show the contents of the header row cells, not the column letters. It is
as if Excel is selecting the column headers as the header row, rather
that the first row of data.

I can get around it by inserting a blank row 2 beneath the header row,
but I would prefer not to have to do this.

The header row is 58.5 height.

Any clues?

Thanks for you help.
Rose