Report not sorting properly

I am trying to run some reports to get summary information but it only works once and then does not sort properly. I am copying the visible cells from one worksheet which is filtered on date and pasting them to another worksheet. I then want to sort column B and subtotal at each change in catergory (B) and then hide the detail so I only get the totals.

This works fine the first time I run it but not again after. I tried clearing the contents of the destination sheet prior to running the macro but it still is not working. Seems to lose the sort. Here is my code>

Sub PurchasesCategory()

    Sheets("Purchases").Select
    Application.Run _
        "'adjusted whangateau shop model (version 1).xls'!MyFilterPurchases"
    Range("A4:G5001").Select
    Selection.SpecialCells(xlCellTypeVisible).Select
    Selection.Copy
    Sheets("PurchaseReports").Select
    Range("A4").Select
    ActiveSheet.Paste
       
       Range("B4").Select
    Application.CutCopyMode = False
    Range("A4:G5001").Sort Key1:=Range("B5"), Order1:=xlAscending, Header:= _
        xlGuess, OrderCustom:=1, MatchCase:=False, Orientation:=xlTopToBottom, _
        DataOption1:=xlSortNormal
    Range("A4:G5001").Select
    Selection.Subtotal GroupBy:=2, Function:=xlSum, TotalList:=Array(6, 7), _
        Replace:=True, PageBreaks:=False, SummaryBelowData:=True
    ActiveSheet.Outline.ShowLevels RowLevels:=2
End Sub

Thanks John
I answered my own question just after I had posted. I was clearing the contents but had not removed the subtotals. Now the macro goes to the destination file first, removes all subtotals, clears contents then goes and gets the new data and it works perfectly. Can't believe I had spent soo many hours for something so simple.
Karen