Excel 2007 and very new to VBA...

I have a userform (named "QAReviewForm") with a combobox (named "cboSupName"). I want it to populate with my named range "SupList".

FYI, the SupList is found on sheet 2, "Administrative Menu" in column E. E1 contains the heading "Supervisors", and my named range formula is

Formula: copy to clipboard 
=OFFSET('Administrative Menu'!$E$2,0,0,COUNTA('Administrative Menu'!$E:$E),1)


My code is has follows:
Private Sub bttnQAReview_Click()

QAReviewForm.Show

End Sub

Private Sub QAReviewForm_Initialize()

Dim rngSupervisors As Range

Dim ws As Worksheet

Set ws = Worksheets("Administrative Menu")

For Each rngSupervisors In ws.Range("SupList")

Me.cboSupName.AddItem Supervisors.Value

Next rngSupervisors

End Sub
When it runs, my form opens and the combobox is there, but nothing appears as options for me to select (yes, I have some values in column E).

Any help is greatly appreciated.