open the excel file, fress Alt + F11 to get into the VBA editor.
In the project pane double click on "this workbook"
Then change the first drop down menu from general to workbook and make sure the second one says open
add the following code
add the folowing code to the before close event for the workbook
Application.ScreenUpdating = False
Application.ScreenUpdating = True
The close routine is probably the long way round but it works