Why can't I run this code from a NotInList function??

My problem is this.  

I have a number of combo's, all of which require the ability to add an extra record to the table from where the list is generated.  I would very much like to do this using a module, but Access seems not to like refering to modules whilst using the NotInList method.  Here's the code, what can be done??  Any help greatly appreciated.

PhilipE

Here's the code that appears for each combo box notinlist function

Private Sub cmbComp1_AfterUpdate()
Call CompetitorNotInList
cmbComp2.Enabled = True
End Sub

Here's the module code called by the combo box code.

Public Sub CompetitorNotInList(NewData As String, Response As Integer)
Dim sMsg As String
Dim sSQL As String
Dim sClient As String ' New entry for combo box
Dim ctlCurrentControl As Control

'Identifies which combo box has focus
Set ctlCurrentControl = Screen.ActiveControl

sClient = [Forms]![ReputationFrm]![cmbClient]

sMsg = "Do you wish to add entry to the list?"
sSQL = "INSERT INTO CompetitorTbl (ClientName,CompetitorName) " & _
        "VALUES ( '" & sClient & "', '" & NewData & "')"

    If MsgBox(sMsg, vbYesNo) = vbYes Then
        Response = acDataErrAdded
        CurrentDb.Execute (sSQL)
        ctlCurrentControl.Undo
        ctlCurrentControl.Requery
            Else
                Response = acDataErrContinue
                ctlCurrentControl = ""
    End If

End Sub