CustomSort crashing my worksheet??

[scoha]

I have a worksheet in which I have placed a Custom sort as follows:

'This bit sorts the OpenIssues according to CustomSort List

    'Deletes any Custom Lists already installed
        For x = Application.CustomListCount To 5 Step -1
            Application.DeleteCustomList (x)
        Next x
    
    ' custom sort order text
    Application.AddCustomList ListArray:=Sheets("Validations").Range("CustomSort")

    ' sort using latest custom sort order entry
    Range("a7:l" & Rows.Count).Sort Key1:=Range("G6"), Order1:=xlAscending, Header:=xlGuess, _
                OrderCustom:=Application.CustomListCount + 1, MatchCase:=False, _
                Orientation:=xlTopToBottom, DataOption1:=xlSortNormal

    ' remove latest custom sort entry order
    Application.DeleteCustomList Application.CustomListCount

Trouble is, ever since I did this I am crashing and corrupting the file - anyone have a clue why this might be so?