Sorry, my bad…  

I was deactivating the edit capability in the InitiateRow event by changing the style to:

template.Cells["CharFrom"].Style = Infragistics.Win.UltraWinGrid.ColumnStyle.FormattedText;
template.Cells["CharTo"].Style = Infragistics.Win.UltraWinGrid.ColumnStyle.FormattedText;

It is fixed now,
Thank you.