Databinding: Add new with checkboxes on Form

Hi, I have a problem with a dataform Application using c# and MS SQL Server 2000. If I only have Textboxes on my form everything works fine (Navigation, Update, Add, Delete). When I also have a checkbox on my form which refers to a TINYINT field in my DB I cant add a new row. Updating and Navigation works fine. When I hit the ADD button on my form the fields does not clean up the fields – even the textfield have their old values. Code for binding the checkbox: chkFieldValue[curCol].DataBindings.Add("Checked", DS_SelTable, "SelTable." + ColName); Code for the add-button: BindingContext[DS_SelTable,"SelTable"].AddNew(); Can anyone help ? Thanks Frank