runtime error 1004 range of object global failed excel 2010

I got this error on Excel 2010, however the code below works perfectly fine on 2007. I changed all the settings on 2010 on Trust Center, but still no go. I am getting the error on the code below (Range("Week" & WeekNo).Copy. Can someone please tell me why this code works in 2007 but does not in 2010? Thanks.

Sub Macro2()

 ' Keyboard Shortcut: Ctrl+z
 '





 Dim wbkOtherWorkbook As Workbook
 ' Set wbkOtherWorkbook = Workbooks("District Foodcost.xls") 'Assuming this workbook is already open


 Dim wbMyBook As Workbook
 Set wbMyBook = ActiveWorkbook
 Set objOutlook = GetObject(, "Outlook.Application")

 Dim MySelection As Range
 Set MySelection = Application.InputBox(prompt:="Select a Cell ie... G3", Type:=8)
 MySelection.Select
 ' ActiveWorkbook.Sheets("Weekly Food Cost").Activate

 Workbooks(1).Activate

 Dim WeekNo As Variant

 Do
 WeekNo = Application.InputBox _
 ("Enter week number", , , , , , , 1)
 If WeekNo = "False" Then
 Exit Do
 End If
 Loop Until WeekNo >= 1 And WeekNo <= 4

 Workbooks(2).Activate
 If WeekNo <> "False" Then 
Range("Week" & WeekNo).Copy
 Workbooks(1).Activate
 ' Windows("District Foodcost.XLS").Activate

 Selection.PasteSpecial Paste:=xlPasteValues, Operation:=xlNone, SkipBlanks _
 :=False, Transpose:=False
 End If
 Dim Wb As Workbook
 For Each Wb In Workbooks
 If Wb.Name <> ThisWorkbook.Name Then
 Wb.Close savechanges:=False
 End If
 Next Wb
 Range("E3").Select
 ' objOutlook.Application.Quit

 End Sub