Combo box change event triggered from another file
 

Hi,
I'm using Excel 2007 and have a workbook that contains a number of ActiveX
combo boxes on different sheets. When this workbook is open I've found that
if I create a new workbook and enter a value to any cell in the new workbook
the change events for each combo box on the active sheet in the original
workbook are triggered! This results in various errors.
However it doesn't happen if instead of creating a new workbook I open an
existing one.
I guess I'm going to have to add code to the combo box change events to
check that the active workbook is the original workbook and exit if not.
However this shouldn't be necessary.
Has anybody come across this behaviour before and if so found any better way
of preventing it?