VBA Code De-bugging in 2010 excel

Looking for some help in debugging some old VBA/Macro code to work in the newer version of MS Excel 2010. The macro in question is the "Material Rollup" function.

The purpose of the macro is after selecting a contiguous range of cells in a given column. Then macro will copy the information corresponding information range (B?:H?) To a new sheet or existing sheet, sort the information according to the values in the "Part #" column (D).

Up to this point the macro works as intended. But it errors out and when it tries to combine items with similar "part #" and delete the duplicate entries. Any help or assistance you can send my way would be greatly appreciated.

The believe the errors/bug starts on the following line "Rollup, Like Part Numbers, Combine Quantities and Delete Rows".

Below is VBA code that has become the bane of my existence.

'**************************  Material Rollup by Part Number  *****************************
Function Material_Rollup()
    MyfirstValue = 0
    MyLastValue = 0
    Cnt = 0
    TopRow = 0
    BottomRow = 0
    CntDelRows = 0
    NewLastRow = 0
    Quantity = 0
    loopCnt = 0
    Dim MyBom As String
    Dim MyRollup As String
    Dim NextRow As String
    MyBom = ActiveSheet.Name
    If Val(Range("A2")) > 0 Or Val(Range("I1")) > 0 Then
        MsgBox MyBom & " is not a BOM72 Work sheet or Material Rollup Sheet, Rollup Canceled."
        Call GotoSheet
        GoTo Cancel
    End If
    ReturnRows (Selection.Address)
    MyfirstValue = My_First_Row
    MyLastValue = My_Last_Row
    If MyfirstValue = MyLastValue Then
        Call BOM72ERR(3, "")
        GoTo Cancel
    End If
RetrySheet:
     'Provide List of existing Sheets and input box for new Sheet Name
     ListSheets (2)
        If Pick_Sheet = "Pick_Sheet_Cancel" Then
            Sheets(MyBom).Select
            GoTo Cancel
           Else
           MyRollup = Pick_Sheet
         End If
     'See if Rollup sheet name exist or is new
    For Each sh In ActiveWorkbook.Sheets
            If UCase(sh.Name) = UCase(MyRollup) Then
                DoesSheetExist = 1
                Exit For
            Else
                DoesSheetExist = 0
            End If
    Next
    'If Sheet exist make sure its a Material Rollup Sheet
    If DoesSheetExist = 1 Then
        If Worksheets(MyRollup).Range("E1").Value <= 0 Then
                MsgBox MyRollup & " is not a Material Rollup Sheet."
        GoTo RetrySheet
        End If
    End If
    'If sheet doesn't exist, build and format
    If DoesSheetExist = 0 Then
        Sheets.Add
        ActiveSheet.Name = MyRollup
        ActiveWindow.DisplayGridlines = False
        With Application
            .Calculation = xlManual
            .MaxChange = 0.001
        End With
        ActiveWorkbook.PrecisionAsDisplayed = False
        Worksheets("Data").Range("A4:W6").Copy (Worksheets(MyRollup).Range("A1"))
        Range("a4").Select
        ActiveWindow.FreezePanes = True
         Range("A5").Select
        TopRow = 4
        Range("E1") = TopRow
    End If
    Worksheets(MyRollup).Select
    TopRow = (Range("E1") + 1)
    BottomRow = ((Val(MyLastValue) - Val(MyfirstValue)) + 1) + Range("E1").Value
    Cnt = TopRow
    Worksheets(MyBom).Range("B" + MyfirstValue + ":H" + MyLastValue).Copy (Worksheets(MyRollup).Range("B" & TopRow))
    'Delete Rows that are not Material Items (Look for Text in Mfg Column)
    For Each C In Worksheets(MyRollup).Range("C" & TopRow & ":C" & BottomRow)
           If C.Value = "" Then
               Rows((Cnt - CntDelRows)).Select
               Selection.Delete Shift:=xlUp
               CntDelRows = CntDelRows + 1
            End If
               Cnt = Cnt + 1
    Next C
    'Delete Rows with the Unit Price column colored Gray (Don't Rollup)
    NewLastRow = (Cnt - (CntDelRows + 1))
    Cnt = TopRow
    CntDelRows = 0
    For Each C2 In Worksheets(MyRollup).Range("G" & TopRow & ":G" & NewLastRow)
           If C2.Interior.ColorIndex = 40 Then
               Rows((Cnt - CntDelRows)).Select
               Selection.Delete Shift:=xlUp
               CntDelRows = CntDelRows + 1
            End If
                Cnt = Cnt + 1
    Next C2
    NewLastRow = (Cnt - (CntDelRows + 1))
    'Sort Rollup by Part Number
    Range("A" & TopRow & ":S" & NewLastRow).Select
    Selection.Sort Key1:=Range("D" & TopRow), Order1:=xlAscending, Header:=xlGuess, _
        OrderCustom:=1, MatchCase:=False, Orientation:=xlTopToBottom
    Range("B" & TopRow).Select
     Cells.Select
     With Selection.Font
         .Name = "Arial"
         .FontStyle = "Regular"
            .Size = 10
     End With
     Range("A1").Select
    Cnt = TopRow
    cnt2 = (Cnt + 1)
    CntDelRows = 0
    loopCnt = 0
    'Rollup, Like Part Numbers, Combine Quantities and Delete Rows
    For Each c1 In Worksheets(MyRollup).Range("D" & TopRow + ":D" & NewLastRow)
            NextRow = Range("D" & cnt2)
           If UCase(c1.Value) = UCase(NextRow) Then
              Quantity = Range("E" & Cnt) + Range("E" & cnt2)
              Range("E" & cnt2) = Quantity
              Rows(Cnt).Select
              Selection.Delete Shift:=xlUp
              CntDelRows = CntDelRows + 1
              Cnt = Cnt - 1
              cnt2 = cnt2 - 1
              Quantity = 0
           End If
             Cnt = (Cnt + 1)
             cnt2 = (cnt2 + 1)
    Next c1
        NewLastRow = NewLastRow - CntDelRows
        'Sort Rollup by Manufacturer then Part Number
        Range("A" & TopRow & ":S" & NewLastRow).Select
        Selection.Sort Key1:=Range("C" & TopRow), Order1:=xlAscending, Key2:=Range _
        ("D" & TopRow), Order2:=xlAscending, Header:=xlGuess, OrderCustom:=1, _
        MatchCase:=False, Orientation:=xlTopToBottom
        Range("B" + TopRow).Select
        Worksheets("Data").Range("G8:W8").Copy Worksheets(MyRollup).Range("G" & TopRow & ":G" & NewLastRow)
        Sheets(MyRollup).Select
        Columns("K:S").Select
        Selection.ColumnWidth = 6
        Columns("A").Select
        Selection.ColumnWidth = 3
        Columns("B").Select
        Selection.ColumnWidth = 20
        Columns("C:D").Select
        Selection.ColumnWidth = 12
        Columns("E:F").Select
        Selection.ColumnWidth = 6
        Columns("H").Select
        Selection.ColumnWidth = 3
        Range("K5").Select
        With Application
        .Calculation = xlAutomatic
        .MaxChange = 0.001
        End With
        ActiveWorkbook.PrecisionAsDisplayed = False
        Range("E1") = NewLastRow
        Range("A" & TopRow) = "WorkSheet: " & MyBom & "    Rows: " & MyfirstValue & " to " & MyLastValue
        Range("A" & TopRow).Font.ColorIndex = 22
        If TopRow > 5 Then
            Range("B1") = "Multi-Rollup Sheet"
            Else
            Range("B1") = "Single-Rollup Sheet"
        End If
        Range("B" + TopRow).Select
        'Don't forget to value quantity column
Cancel:
End Function

Thank you for any help you can offer.