It doesn't seem that you actually ended up asking a question here.
Well, I don´t know why you don´t see my question or maybe you just didn´t understand it.
I´ll try to explain it better.
One of the columns in my report has more than 1 result. The column tells the countries where our system exists. I don´t want one row for each country and therefore I created a calculated field to get all countries in the same column in the same row. The countries are separated with a comma-charachter like "Denmark, Sweden, Norway, Finland". The report includes many other columns. When any of the other columns doesn´t have any value but NULL-value the column with my calculated field is also empty. If I update the empty column with a value then the column with calculated field show the countries again. So, is it something in the SQL of this predefined calculated field that doesn´t work. Maybe it´s a known error?'