> As for your GC concerns: Can you construct a more elaborate example? If 
> your environment experiences a severe memory issue, you should just try 
> to clean-up the system like in the release process:

I have no problem in my images, it's just by perusing the code that I 
saw that #userInterfaceTheme requires a specific handling.

What worries me is not the normal usage of #userInterfaceTheme, which 
works fine, it is how technically easy it is to mess things up, although 
I do not see that happening too often or at all actually. But if it 
happens sometime, somewhere, it will be a silent bug difficult to diagnose.

BTW I see that the #cleanUp: method will indeed reset all stacks in 
hard-coded subclasses of UserInterfaceTheme, but it will not do so for 
possibly existing other subclasses. So if I create my own 
MuOInterfaceTheme for example, I will also need to monkey-patch 
#cleanUp:.. Maybe we should iterate long #allSubclasses?

Stef