It was not possible, to save a session
(error writing files)

I added following lines to make it work.
> (inserted lines)

import wx.lib.dialogs
>import stat

>DrFrame.farray = map(lambda document: document.filename, DrFrame.txtDocumentArray)
               
        if (dlg.ShowModal() == wx.ID_OK):
            sessionfilename = dlg.GetPath().replace("\\", "/")