Here is what I thought would work with symbols-
There is a symbol with 2 timelines, Main and Show text.
There is an icon, and it has an action on it for mouseover, where it goes to the ShowText Timeline, and displays some text. This works very well in the symbol. Mousing over shows text
There is also a mouse out action, and it goes to the Maintimeline (where the text is not visible). On mouse out is set to run this timeline, but mousing out does not hide the text.
So I thought that I would be able to create a third timeline (hide text) that I would run to remove text, but that doesn't work. It seems that objects have a global set of properties, and they can cannot be set to different values in different timelines.