MS Excel Objects Lock Row based on Value working with Other Objects

I have programming, with major help from others, that works great for two separate workbooks. The problem is that I can't seem to have them both work within the same workbook and I don't know why.

We have a large contact database (4800 rows) workbook with a lot of sorting macros. I use the following to allow the user to double-click a cell to select or de-select a contact. This is under the Excel Objects, Sheet1 (MASTER):

Private Sub Worksheet_BeforeDoubleClick(ByVal Target As Range, Cancel As Boolean)
    'Limit Target count to 1
    If Target.Count > 1 Then Exit Sub
    'Isolate Target to a specific range
    If Intersect(Target, Range("SelectionMaster")) Is Nothing Then Exit Sub
    'set Target font tp "marlett"
    Target.Font.Name = "marlett"
    'Check value of target
    If Target.Value < "a" Then
        Target.Value = "a" 'Sets target Value = "a"
        Cancel = True
        Exit Sub
    End If
    If Target.Value = "a" Then
        Target.Value = "r"
        Cancel = True
        Exit Sub
    End If
    If Target.Value = "r" Then
        Target.ClearContents 'Sets Target Value = ""
        Cancel = True
        Exit Sub
    End If
    End Sub

In another workbook, I tested the following for locking a particular row if an 'X' is placed in Column AZ (end of contact data). This is under the Excel Objects, Sheet1 (Sheet1):

Option Explicit

Private Sub Worksheet_Change(ByVal Target As Range)
    Dim LR As Long
    If Not Target.Column = 52 Then Exit Sub
    If Target.Count > 1 Then Exit Sub
    If UCase(Target.Value) = "X" Then
        ActiveSheet.Unprotect
        Target.EntireRow.Locked = True
        ActiveSheet.Protect
    End If
End Sub


Private Sub Worksheet_SelectionChange(ByVal Target As Range)
    If Target.Locked Then
        If MsgBox("Row is locked. Do you want to change the value ?", vbYesNo) = vbYes Then
            ActiveSheet.Unprotect
            Target.EntireRow.Locked = False
            Cells(ActiveCell.Row, 52).Value = ""
            ActiveSheet.Protect              
        End If
    End If
End Sub

In the Database file, I have certain rows that identify the contact's category that I would like to have locked. All other cells can be changed. If I copy over the 2nd code to the database file, it doesn't work correctly. Instead it locks all of the cells and prompts the message box regardless of an 'X' in Column AZ. Can these two not co-exist or what is this newb doing wrong?

Thanks!