I have a shapefile containing population data for Baltic countries. Using the SQL formula: $rownum in the field calculator, I was able to create an automatic numbering of rows (far right on the picture below), from 1 to the end of my table. However, for no apparent reason, the numbering is broken at row 129 and switches to 766. It changed at the exact place where I have a new country, so maybe it is linked.
Any reason why this happens?