From VBA, I start with an excel workbook with one worksheet. Then, I open a
second excel file (with one worksheet), edit it and bring the tab into the
original workbook. So, there are now two worksheets in the original workbook.
Then save it - this works. Then, do it again... Open a new second excel file,
edit the tab and bring it into existing workbook. Now there are 3 tabs in the
original workbook. I try to save and it gives an error "document not
saved"... using the following code:

Workbooks.Open ("\\...path\Summary.xls")
Windows("Summary.xls").Activate
Sheets("Tab1").Select
Sheets("Tab1").Move befo=Workbooks(Original).Sheets(1)
ActiveWorkbook.Save