shrinking pop up calendar

Hi All
pop up calendar excel office 2003

Here spreadsheet with pop up calendar in columns A 8 to A200 & G8 to G200 calendar works great till I reduce in zoom size from 100% to 85% for spreadsheet to fit screen then calendar also reduces the same but part of calendar disappears any way to stop this or enlarge calendar so all shows
& each time I save then go back the calendar shrinks each time it's closed & saved it gets smaller till you can no longer see it have I made mistake in VBA

the V B A

Private Sub Calendar1_Click()
ActiveCell.Value = CDbl(Calendar1.Value)
ActiveCell.NumberFormat = "dd/mm/yyyy"
ActiveCell.Select
Calendar1.Visible = False
End Sub

Private Sub Worksheet_SelectionChange(ByVal Target As Range)
If Target.Cells.Count > 1 Then Exit Sub
If Not Application.Intersect(Range("A1:A20,c1:c20"), Target) Is Nothing Then
Calendar1.Left = Target.Left + Target.Width - Calendar1.Width
Calendar1.Top = Target.Top + Target.Height
Calendar1.Visible = True
' select Today's date in the Calendar
Calendar1.Value = Date
ElseIf Calendar1.Visible Then Calendar1.Visible = False
End If
End Sub


please find attached
Many thanks
Ralph