Can't save new rows via Grid

I've a Grid with the editor enabled.

DateField df_tmp = new DateField();
        df_tmp.setConverter(new DateToTimestampConverter());

        Grid g = new Grid();
        g.setContainerDataSource(someSQLContainerFromOracle);
        g.setEditorEnabled(true);
        g.getColumn("ORACLE_DATE").setEditorField(df_tmp);

I've a button which adds another row to the grid:

Button save = new Button("Add");
        save.addClickListener(new Button.ClickListener() {
            
            @Override
            public void buttonClick(ClickEvent event) {
                
                getOverview().editItem(getOverview().addRow(new java.sql.Timestamp(new Date().getTime())));
                
            }
            
        });

`GetOverview()` returns the describe Grid.

As I click this button, a new row is generated and starts automatically in "Edit" mode since `addRow()` returns the generated `ItemId` as a parameter to `editItem()`.

I add a new row edited it a little bit and hit save. The problem is that this new data-set never reaches the database even though there is no exception thrown. There are a few things to hold in mind:

- The Grid doesn't update any item

It provides each data-set from the table but doesn't update any of it. It's changeable without an exception but the changes never reach the database.

- The UI isn't updated

As one row is changed and saved, the view remains the same. However, if you edit this data-set again, you're provided with the updated fields.

 - A commit is made

I'm able to provoke a `commit()` exception if I don't use a custom converter for the DateField (`df_tmp.setConverter(newDate(...))`). So we can suggest that a commit is executed.

 - The primary key is updated via a trigger

Thus I don't provide a key with `addRow()`.