It's still not working on my actual sheet. What I do, step by step,
is:

1. I import a text file which is a list of data running vertically.
One entry per line.
2. On the sheet to which it is imported, I have set it up so certain
cells are assigned the contents of each imported cell, basically going
across.
3. I copy the contents of these cells into a new sheet and paste them
starting on the next available line.

I deleted the contents of all cells and formatted them to text, then
tried to import again. It still gave me the same problem of putting
"1-a" at the botttom of the sheet when I sorted. What am I missing? I
wonder if I should rebuild the sheets from scratch. I can do this but
it is time consuming so I'd like to know if you think that would work.
Thanks,
Peter