Subclasssed control’s perimeters appearing/disappearing?

I subclassed a MacOSLib’s Cocoa.NSImageView Object to add some event definitions and methods in order to have an automated button class. When I do this, the rectangle on my sample window disappears and the subclass control is only shown as a generic object on the window row where timers and the like are listed.

In my compiled app, everything behaves as usual. And the editor allows me to place the object anywhere on my window, although it will only be shown as mentioned.

Anyway, I needed another subclass to handle my custom events. When I set one up and change the window objects to this new subclass, the generic object disappears and the control’s borders are shown again.

I think this is not the intended behavior, or did I miss something? I also noticed the new events will not be shown from their birth onwards, but I have to click some other items in my control list and return to the object later, after which the instantiated objects will show the custom events. Up to then, only the subclass shows them, not its instantiated children. But I bet the latter is known somewhere in Feedback.