When I create a invoice form (with writer) I found the following problem: 

1. I create a table with 6 columns / 5 lines.
2. The columns are named as follow

Pieces | Description  | unit price | total price

3. Multiply 'Pieces x unit price = total price' ==> ok.
4. Then I create a new table, at the end of the first table, for the invoice
amount (amount of all total prices) in the form: '=<Tabelle1.D2:D5>'.

5. The problem is, when I insert a new line (after the last line in the first
table), the formula was not updated in the second table to ''=<Tabelle1.D2:D6>',
so the 'Invoice amount is wrong'. 
When I insert the line before the last line the formula was updated.