problem with duplicate row and auto increment value

I have a table where the primary key is set by an autoincrement.
When i use the duplicate row, i get displayed a 0 instead the autoincrement value.
When i afterwards try to update the row it says that it can not update the row. It says 0 rows updated when 1 should be updated. There is a very simple workaround. When the row is added, i press again apply filter and the primary key gets the proper value.