@Peter – sometimes it's hard to get through to buttons inside MSOs that are placed inside Scrollable Frames.
Check the layers panel for objects to select thiese.
It would be great if we could expand the layers panel to show all objects inside every state of an MSO, not only the active one. And I'd like to do a restricted view of "all MSOs" or "all buttons" in the layers panel inside of a selected object. Generally spoken: a restricted view for distinct object classes.
@Uwe - The idea to see all a particular type of object is great.
I find that when I create MSO i will start off by using layers to create each state, once im done creating the states, I just have to go to each layer and group the objects together, then create the MSO. However, when I have created the MSO, it becomes one object in one layer, so when i wanted to edit a particular state, I have to go to the MSO panel to find the state instead of using the layers to hide/view the states, and it was confusing, so i would copy the state out to another layer to do the editing then copy it back. My method seems a bit inefficient though so i figured ill ask around how people are doing it.