With this example you can reproduce it easily :

view := RTView new.

box := RTBox new color: Color green.

label := RTLabel new.

el := (RTCompositeShape new shape1: box; shape2: label).

el :=  (RTHorizontalCompositeShape new shape1: el; shape2: (RTEllipse new color: Color red)) elementOn: 'Hello World'.

view add: el.

view addMenu: 'Color' callback: [ el shape shape2 color: Color blue. el update. view signalUpdate ].

view open 

And even if I don't have a composite shape composed with another composite shape, the update is not good.