Calender autorange problem on locked worksheet

Gents

I've a small problem. I'm using the following code to conditionally lock parts of my worksheet dependant on a lock/unlock statement.

I also want to use a popup calendar which i found on this site (apologies for not recalling whose)

The problem appears to be that the lock code prevents the calendar from autofitting thus generating a "autofit method of range class" error/

What I'd like to do is either get the lock/unlock code to accept the date input or alter the calendar code to prevent the autofit error

first the lock/unlock code

Option Explicit

Private Sub Worksheet_Change(ByVal Target As Range)
Dim Cell As Range
Dim WS As Worksheet
Set WS = Target.Parent
WS.Unprotect
For Each Cell In Target
    If Cell.Column = 21 Then
        If Cell = "Lock" Then
            Range(Cells(Cell.Row, 1), Cells(Cell.Row, 10)).Locked = True
        ElseIf Cell = "Unlock" Then
            Range(Cells(Cell.Row, 1), Cells(Cell.Row, 10)).Locked = False
        End If
    End If
Next Cell
WS.Protect
End Sub

Now the calendar code, the point that the debug stops is in red.

Option Explicit
'use a class module to create a collection of commandbuttons

Public WithEvents CmdBtnGroup As MSForms.CommandButton

Sub CmdBtnGroup_Click()
    If Left(CmdBtnGroup.Name, 1) <> "D" Then Exit Sub
    If Month(CDate(CmdBtnGroup.Tag)) <> frmCalendar.CB_Mth.ListIndex + 1 Then
        Select Case _
               MsgBox("The selected date is not in the currently selected month." _
                      & vbNewLine & "Continue?", _
                      vbYesNo Or vbExclamation Or vbDefaultButton1, "Date check")
            Case vbYes
                If g_bForm Then
                    GoTo on_Form
                Else: GoTo addDate
                End If
            Case vbNo
                Exit Sub
        End Select
    Else:
        If g_bForm Then
            GoTo on_Form
        Else: GoTo addDate
        End If
addDate:
        With ActiveCell
            .Value = CDate(CmdBtnGroup.Tag)
            .EntireColumn.AutoFit        
End With 
with frmCalendar
            .lblWeekNum.Caption = "Week number: " & VBAWeekNum(CmdBtnGroup.Tag, 2)
            .lblISOweekNum.Caption = "ISO Week number: " & IsoWeekNumber(CmdBtnGroup.Tag)
            .lblDayNum.Caption = "Day number: " & DayOfYear(CDate(CmdBtnGroup.Tag))
            .lblZodiac.Caption = "Zodiac sign: " & ZodiacSign(CDate(CmdBtnGroup.Tag))
            .Height = frmHeight2
        End With
        GoTo chg_month
on_Form:
        g_sDate = CmdBtnGroup.Tag
chg_month:
        With frmCalendar.CB_Mth
            .ListIndex = Month(CmdBtnGroup.Tag) - 1
        End With
    End If
    'unload the form after adding date
    '    Unload frmCalendar
End Sub

Any help is appreciated, I'm happy that the conflict is with the lock/unlock as the calendar works lovely without it.