@Kronos: i have found the problem, i have installed PanelApp too "Ram Disk:" and seems the space in the path is a problem.

Now prefs is launched after a new installation on a partition.

Some suggestions:

- Maybe named the prefs window like "Panels prefs"

- Maybe add version strings for PanelApp and PanelPrefs

- Drag'n drop icon to panels or Panels prefs will be fine.