Hmm,

It works with
START "" /WAIT CALC
START "" /WAIT NOTEPAD

Notepad doesn't start before I exit calc....

You are right about Datastream. It is an axcel add-in that has a
workbook_open macro. This is why I have to use an auto_open.
Otherwise, my Datastream macros would not work when I enter the file
manually and press escape to cancel the auto_open. (I'm aware of
pressing shift, but MS disabled it in Office XP (or Win2k don't
remember)