[hunguponword]

I am using Table-forumula feature in some columns of a table. The table grows
over time with addition of new lines. Periodically, I copy the Total line and
paste it at the bottom, under the lines that have been appended below the
earlier total line. Then I delete the original (now interleaved) total line.
The formulas move down along with the rest of the total line. Until now, this
has worked fine...and I have gotten an accurate totals update whenever I
"moved" the totals line down and invoked Table-Formula from the standard menu
bar. However, now, when I click the total cell, then open the Table menu,
then click formula...I no longer get the total pasted into the cell. Instead,
a message appears in its place, exactly as follows:
! Table Index Cannot Be Zero

I'd like to understand better what a table index is. Is is a hidden code,
like in Wordperfect, or something else. What might have caused the "error"?
How can I find and correct the table index--or do whatever else is
necessary--so that the formula operation will again work? What might I have
done to mess up the table index? So I can avoid doing it again? Thank you.