Yes, I can reproduce it (took some work to narrow it down).  Problem
seems to only occur when I call {EV_TITLED_WINDOW}.enable_user_resize.

To reproduce:
Compile with attached classes and .ecf file.  With 5.7, window resizes
to accomodate buttons in upper bar of window and cannot be resized
smaller.  With 6.0, window does not resize wider to accomodate buttons.
Window can be any width and buttons are "squished" together and end
up overlapping each other.

Please fix if this is a bug or tell me how to work around it.