When I freeze one or more rows, and then I click a single column header and
sort by that column, sometimes the frozen rows are included in the sort, and
sometimes they are not. I don't ever want them to be included, so I'm trying
to figure out what is causing this to happen and how to prevent it.

For example, say I have a "Name" column containing three rows: Tom, Dick,
and Harry. The top row (containing the header) is frozen. If I sort by that
column, I'd expect "Name" to stay in the top row, and the other rows to be
sorted Dick, Harry, and Tom. Sometimes this works exactly as I'd expect, but
other times the column header is included in the sort, so I'll end up with
rows sorted as Dick, Harry, Name, and Tom.

This can really mess things up when I have, say, 6 rows containing a sheet
title, user instructions, and header data frozen at the top and I don't want
any of these rows to be included when sorting. Can anyone tell me how to
control this?