Well, today I've solved some problems using wxWidgets for Mutabor.
The first one was, that my focus changes are not shown on Microsoft Windows. The reason is simple: Microsoft Windows does not allow to change the border of a window. Even if it is a child of another one! So, I changed the corresponding drawing routines to draw a border on wxMSW when the corresponding shape is focused.
The other problem is linked with wxStaticText. I'm using this class to draw the text in the routing window. Unfortunately this causes some trouble on Windows. Though the shape is entered as parent and doesn't have the tab traversal bit set, hitting the tabulator key focuses the labels, too. Since this behaviour is not intended (it should work like the Icons on Desktop or in the Windows Explorer), I had implement my own class, to forbid keyboard focus.