Does anyone know why this happens?
This is my usual workflow for creating various sized web banners.
1. Create a 300 x 250
2. Get it approved
3. When approved, duplicate the document and resize it for 160 x 600, 728 x 90 etc etc and reposition / change movie clips to fit the new sizes
A problem keeps occuring that if I modify a movie clip in one document those changes can affect other documents even if they are closed.
I haven't created any Project files so essentially the documents aren't linked to each other so why do they change?
Thanks that gave me something to investigate but alas no, I checked all the symbols properties and nothing is checked for runtime sharing.
Any other thoughts?
I might try renaming all symbols when I duplicate a document but that seems a lot of work.
If you don't have anything marked as runtime sharing that is the only thing that would modify the symbols. Once you duplicate a .fla file it does not have a magical connection to the others. I would just audit your process and make sure you are modifying what you actually intend to modify.
Are you modifying any external assets outside of the FLA that maybe they are all still pointing to?