Macro To Combine Worksheets And Workbooks

I've got a macro that combines multiple worksheets and workbooks. Just a minor problem, the very last row of each worksheet is being deleted, and I can't seem to pinpoint the cause of the problem.

'This will copy data from all sheets of the selected workbooks
'To a sheet named 'Data' in the sheet in which the macro is run from

Dim pasterow As String
mainsheetname = ActiveWorkbook.Name
MsgBox ("Please select spreadsheets to combine")
filestoopen = Application. GetOpenFilename(MultiSelect:=True)
responseval = MsgBox("Do you want to leave the combined spreadsheets open?", vbYesNo)
Worksheets("Data").Select
Range("A1").Select
'open workbooks
For Each w In filestoopen...................