For anybody that might be interested, here is an example script that has a dropdown menu, slider and text item that all interact with each other. There appears to be an anomaly such that when you change a component's value via code, its onChange event handler is called (which really should only be called when the user makes a change to a component value, not the code -- which can manually call the component's 'notify' or 'onChange' method directly if needed).
If you download and run it, you can see how this anomaly:
1) causes a "jumping slider" as you drag it
2) makes the text field practically useless as an input method
P.S. Andrew, feel free to move this to "Bugs" if you think that is where this belongs