Have a look into your used object styles if something has changed. If you do not work with object styles you should not wonder if those problems appear.
Select your object and look in the effects panel to see where you put the Outer Glow. If it's in the wrong place, you can move it or delete it and reapply it. What is it currently assigned to?
Not sure what you are asking with your second question, but if you may have set it as a default. If it is for all documents, then close all documents, then choose Overprint. If that does not work, you may have to reset your defaults.
Thanks for the answers; I checked the settings before posting the question, all was in order.
Yet the problem has magically solved itself today. After starting up ID, everything was correctly applied again. May have been a strange cache/preferences conflict or something.