Bugs:
=====
 
- Curses on Solaris will have output frozen if key-presses
  arrive during updating or drawing or so. It's best seen in the
  progress-bar dialog demo. If you press a key halfway, the
  screen will freeze. The application however, will continue
  running! ---> bug in curses that was shipped with the
  system. Using NCurses -> OK! I do not know if there is
  a workaround for this.

- Curses::UI has a strange behavior when recursively creating
  widgets. If you e.g. create a Listbox out of a Listbox and
  delete the originating Listbox the visible focus gets lost
  though it reacts on keystrokes. Seems to be a problem with
  closures and such stuff, but I haven't figured it out yet.