Hi Mike

 Thnak you for your reply

/* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;}

To answer your questions - Iam assigning the UltraComboEditor to the cells in the BeforeRowActivate by calling

Private Sub GetValueList(ByVal oUltragridRow As UltraGridRow)
        Const scRoutine As String = "frmClinicalAudit. GetValueList"

        Dim sFindingkey As String = Nothing
        Dim theSettings As New DefaultEditorOwnerSettings
        Dim theOwner As New DefaultEditorOwner(theSettings)
        Dim theEditor As EmbeddableEditorBase = Nothing

        Dim sFindingValueKey As String = Nothing
        Dim sFindingValueDesc As String = Nothing

        Dim sValueKey As String = Nothing
        Dim sValueDesc As String = Nothing

        Dim oDataReader As SqlClient.SqlDataReader = Nothing
        Dim sSQL As String = Nothing
         Dim uce As UltraComboEditor = New UltraComboEditor

        Try

            Call goErr.Log("start " + scRoutine)

            uce.Name = "oUltraComboEditor"
            uce.DropDownListWidth = -1 ' fit the widest text
          
            sSQL = oUltragridRow.Cells("SQLToGetValues").Text

            If Len(Trim(sSQL)) <> 0 Then

                sFindingValueKey = Trim(oUltragridRow.Cells("ValueListValueColumn").Text)
                sFindingValueDesc = Trim(oUltragridRow.Cells("ValueListDisplayColumn").Text)

               oDataReader = goLassoDB.GetDataReader(sSQL, True)
                Do While oDataReader.Read() = True
                    sValueKey = Trim(goLassoDB.GetString(oDataReader, sFindingValueKey))
                    sValueDesc = Trim(goLassoDB.GetString(oDataReader, sFindingValueDesc))
                    uce.Items.Add(sValueKey, sValueDesc)
                Loop

                oUltragridRow.Cells("Value").EditorControl = uce
               oUltragridRow.Cells("Value").Style = ColumnStyle.DropDownValidate

                'close the SQL reader
                oDataReader.Close()
            End If
        Catch
            'close the SQL reader
            oDataReader.Close()

            Call goErr.HandleRoutineError(scRoutine)
        End Try
    End Sub
 

I think that it is mostly workign now except for two issues

a) The amount of time i spen 'researchign the use of the LimitToList property you probably wouldn't believe ONLY toi fianlly find that as as Editor this is useless and I needed to set   oUltragridRow.Cells("Value").Style = ColumnStyle.DropDownValidate for the equivalent of the LimitToList feature to work

b) Perhaps most importantly I have handled the error from the DropDownValidate event  as per the following

Private Sub oUltraGrid3_Error(ByVal sender As Object, ByVal e As Infragistics.Win.UltraWinGrid.ErrorEventArgs) Handles oUltraGrid3.Error
        Const scRoutine As String = "frmClinicalAudit.oUltraGrid3_Error"
        Dim Response As MsgBoxResult
        Try
            If e.DataErrorInfo.Row.Cells("AllowQuickAdd").Text = "True" Then
                Response = (MsgBox("The Value that you entered for '" + e.DataErrorInfo.Row.Cells("Finding").Text + "' Was not found - Do you want to add that value to the list?", MsgBoxStyle.YesNo, "The value entered for:" + e.DataErrorInfo.Row.Cells("Finding").Text + " was not found"))
                If Response = MsgBoxResult.Yes Then
                    Call QuickCareProviderAdd()
                    Call GetValueList(e.DataErrorInfo.Row)
                End If

                e.Cancel = True

            End If

            oUltraGrid3.DisplayLayout.Bands(0).Columns(e.DataErrorInfo.Cell.Column.Index).InvalidValueBehavior = InvalidValueBehavior.RetainValueAndFocus

        Catch ex As Exception
            Call goErr.HandleRoutineError(scRoutine)
        End Try

Now here is the very interesting part unless I pressed the 'Escape' key the applciation would get an unhandled exception error after updaing the drop[ down lists via calling     Call GetValueList(e.DataErrorInfo.Row) from oUltraGrid3_Error However Now I have added

Private Sub oUltraGrid3_CellDataError(ByVal sender As Object, ByVal e As Infragistics.Win.UltraWinGrid.CellDataErrorEventArgs) Handles oUltraGrid3.CellDataError

        Const scRoutine As String = "frmClinicalAudit.oUltraGrid3_CellDataError"
        Try

            Call goErr.Log("start " + scRoutine)
            e.StayInEditMode = False

        Catch ex As Exception
            Call goErr.HandleRoutineError(scRoutine)
        End Try
    End Sub

AND now the app no longer issues the unhandled exception error. It seems that the   e.StayInEditMode = False was the key

However, while it is working almost as I'd like it to now (except that the user cursor is not in the column that I'd like it to be) it that seems odd to me that toggling the e.StayInEditMode = False avoids an unhandled exception error that seem to be coming from the Ultragrid components

Also it is my 10 cents worth that there is a VERY real need for some documentation on the differences between the use of the controls as typicaly Windows forms controls and as WinGrid Editors (e.g    LimitToList not applicable use ColumnStyle.DropDownValidate instead would have saved me about oh 3 hours (or more) of 'trial and error') 

Thanks for your help and feedback