Hi Ed. After your changes, I still get: Traceback (most recent call last): File "/Users/tlinnet/software/relax_trunk/gui/input_elements/sequence_2D.py", line 113, in open_dialog self.selection_win_show() File "/Users/tlinnet/software/relax_trunk/gui/input_elements/sequence_2D.py", line 134, in selection_win_show self.sel_win.Close() File "/Library/Frameworks/Python.framework/Versions/7.3/lib/python2.7/site-packages/wx/_core.py", line 14564, in __getattr__ raise PyDeadObjectError(self.attrStr % self._name) wx._core.PyDeadObjectError: The C++ part of the Sequence_window_2D object has been deleted, attribute access no longer allowed. When I try to use the dx.map functionality.