Unhide Rows problem

I have a print macro that I want to run which first verifies if I want to print a memo with the other info. The memo is from row 4 to row 13. I want the memo to be hidden (which works with the following macro) if I choose no memo. But I want it to reappear if I choose yes. Why does the following work to hide the rows but not unhide them?

Public Sub PRNV()
Dim MM As Worksheet
Set MM = Sheets("MEMO")
Chk = MsgBox("WOULD YOU LIKE TO PRINT THE MEMO PORTION?", vbYesNoCancel, "MEMO CONFIRM")
Select Case Chk
Case vbYes
Application.Goto Reference:="R4C1:R13C1"
Selection.EntireRow.Hidden = False
MM.Range("A1").Select
MM.PrintOut
Case vbNo
MM.Rows("4:13").Select
Selection.EntireRow.Hidden = True
MM.Range("A1").Select
MM.PrintOut
Case vbCancel
Exit Sub
End Select
End Sub

I've tried:

MM.Rows("4:13").Select
Selection.EntireRow.Hidden = False

instead of the goto reference section, but that doesn't work either. The rows still remain hidden. Any help is greatly appreciated. Thanks.