DnD from other application

Hi,
I'd like to have a DropTarget for text which is dragged from e.g. a console
window (linux/wxGTK KDE). In the following script I subclassed PyDropTarget and
used a CustomDataObject just in case the text is not transfered as pure text (is
it?). As expected the OnXXX methods of the drop target are being called when
dragging/dropping anything on the target but OnData is never called. So I can
say that and where something has been dropped but I can't access the data. What
am I doing wrong?

import wx

class Frame(wx.Frame):
    def __init__(self, parent):
        wx.Frame.__init__(self, parent, -1)

        self.panel = wx.Panel(self, -1)
        sizer = wx.BoxSizer(wx.VERTICAL)

        self.btn = wx.Button(self.panel, -1, "drop here")
        sizer.Add(self.btn, 1, wx.EXPAND)

        self.panel.SetAutoLayout(True)
        self.panel.SetSizer(sizer)

        dt = DropTarget(self.btn)
        self.btn.SetDropTarget(dt)

class DropTarget(wx.PyDropTarget):
    def __init__(self, window):
        wx.PyDropTarget.__init__(self)
        #self.do = wx.TextDataObject()
        self.do = wx.CustomDataObject('custom')
        self.SetDataObject(self.do)

    def OnEnter(self, x, y, d):
        print 'on enter'
        return d

    def OnDragOver(self, x, y, d):
        print 'on drag over'
        return d

    def OnLeave(self):
        pass

    def OnDrop(self, x, y):
        print 'on drop'
        return True

    def OnData(self, x, y, d):
        print 'on data'
        self.GetData()
        print self.do.GetData()
        return d

class App(wx.App):
    def OnInit(self):
        self.frame = Frame(None)
        self.frame.Show(True)
        return True

app = App()
app.MainLoop()

Regards, Christian