Run Time Error 52- bad file name or number

I'm using the following code to locate all target xls files, open them, and check to see the last used cell in column A.

Everything was working until I added the code to actually open the files and check the last used row; but now I'm getting a RTE 52 (bad file name or number), most often at the line marked with '*** below.

The weird thing is that when I select 'debug' at the error, then debug.print Fil or debug.print UCase(Left(Dir(Fil), 5)), it gives me a valid result- it has the next filename just fine, but something else is going on and I haven't been able to figure it out. I tried with and without setting a new excel application for opening new files, and neither made a difference.

I've also tried adding a 5 second wait where the DoEvents are, that didn't help. Is there a way to set timeout settings for a network drive, similar to what is shown here for http servers? http://msdn.microsoft.com/en-us/library/ms760403.aspx

Any help would be greatly appreciated!
Using XL2003 on WinXP
Keith
(apologies- at least in preview mode, all my code is left justified, even though in the text section I'm typing in, it is all indented)

Option Explicit
 
Sub SrchForFiles()
     ' Searches the selected folders and sub folders for files with the specified
     'extension.  .xls, .doc, .ppt, etc.
     'A new worksheet is produced called "File Search Results".  You can click on the link and go directly
     'to the file you need.
    Dim i As Long, z As Long, Rw As Long
    Dim ws As Worksheet
    Dim y As Variant
    Dim fLdr As String, Fil As String, FPath As String
    Dim LocName As String
    Dim PString As String
    Dim SummaryWB As Workbook
    Dim SummaryWS As Worksheet
    
    'grab current location for later reference, for where to paste final data
    Set SummaryWB = Application.ActiveWorkbook
    Set SummaryWS = Application.ActiveWorkbook.ActiveSheet
        
    y = "xls"
    'actual directory path masked for public posting
    fLdr = "\\share.companyname.com\directory\subdirectory\"
    
    'Application.ScreenUpdating = False
     
    With Application.FileSearch
        .NewSearch
        .LookIn = fLdr
        .SearchSubFolders = True
        .Filename = y
        Set ws = ThisWorkbook.Worksheets.Add(Sheets(1))
        On Error GoTo 1
2:                              ws.Name = "FileSearch Results"
        On Error GoTo 0
        If .Execute() > 0 Then
            For i = 1 To .FoundFiles.Count
                Fil = .FoundFiles(i)
                'screen for target file names ("Multi*.xls")
                If UCase(Left(Dir(Fil), 5)) = "MULTI" Then '*** THIS IS WHERE IT BAILS
                    'Exclude the template file that has no unique file ID, and is therefore only 34 chars long
                    If Len(Dir(Fil)) > 34 Then
                        'Remove the standard naming convention (left 31 characters of filename)
                        LocName = Right(Dir(Fil), Len(Dir(Fil)) - 31)
                        'Remove the ".xls" from the end of the filename
                        'Remainder of the filename (LocName) is the unique file ID
                        LocName = Left(LocName, Len(LocName) - 4)
                        
                        'Get file path from file name
                        FPath = Left(Fil, Len(Fil) - Len(Split(Fil, "\")(UBound(Split(Fil, "\")))) - 1)
                        'Get file information
                        If Left$(Fil, 1) = Left$(fLdr, 1) Then
                            If CBool(Len(Dir(Fil))) Then
                                z = z + 1
                                ws.Cells(z + 1, 1).Resize(, 5) = _
                                Array(Dir(Fil), _
                                LocName, _
                                FileLen(Fil) / 1000, _
                                FileDateTime(Fil), _
                                FPath)
                                ws.Hyperlinks.Add Anchor:=Cells(z + 1, 1), _
                                Address:=.FoundFiles(i)
                            End If
                        End If
                        
                        'open the file and grab the data
                        'Dim oExcel As Excel.Application
                        'Dim oWB As Workbook
                        'Set oExcel = New Excel.Application
                        Workbooks.Open (Fil)
                        DoEvents
                        'Set oWB = oExcel.Workbooks.Open(Fil) 'Workbooks.Open(.FoundFiles(i1))

                        Dim LastRow As Long
                        LastRow = Sheets(1).Cells.Find(What:="*", After:=[A1], SearchOrder:=xlByRows, SearchDirection:=xlPrevious).Row
                        LastRow = qexc_GetLastFilledCellInColumn 'Sheets(1).Range("A1").End(xlDown).Select
                        PString = PString & vbCrLf & LastRow

                        'Workbooks.Close 'Fil
                        Workbooks(Dir(Fil)).Close SaveChanges:=False
                        DoEvents

                        
                    End If
                End If
            Next i
        End If
    End With
     
    MsgBox PString
          
    With ws
        Rw = .Cells.Rows.Count
        With .[A1:E1]
            .Value = [{"Full Name","Location","Kilobytes","Last Modified", "Path"}]
            .Font.Underline = xlUnderlineStyleSingle
            .EntireColumn.AutoFit
            .HorizontalAlignment = xlCenter
        End With
        .[F1:IV1 ].EntireColumn.Hidden = True
        On Error Resume Next
        Range(Cells(Rw, "A").End(3)(2), Cells(Rw, "A")).EntireRow.Hidden = True
        Range(.[A2 ], Cells(Rw, "C")).Sort [A2 ], xlAscending, Header:=xlNo
    End With
     
    'Application.ScreenUpdating = True
    Exit Sub
1:          Application.DisplayAlerts = False
    Worksheets("FileSearch Results").Delete
    Application.DisplayAlerts = True
    GoTo 2
End Sub

Function qexc_GetLastFilledCellInColumn() As Integer
    Sheets(1).Cells(65536, 1).Select
    Selection.End(xlUp).Select
    qexc_GetLastFilledCellInColumn = Selection.Row
End Function