Cannot create new row inside DataGridColumnStyle

Question

I have made a class which implements DataGridColumnStyle called DataGridColumnStyle. But I have encountered a problem. Normally when the user enters something into the last row, a new row is automatically created below it. I cannot recreate this behaviour. I have tried to use AddNew from CurrencyManager in the overridden method Edit, but with no luck. Has anybody experienced similar problems? Best Regars Jóan Petur