In a python program I am writing, I get an error saying 
Traceback (most recent call last):
File "/Applications/Canopy.app/appdata/canopy-1.4.0.1938.macosx-   x86_64/Canopy.app/Contents/lib/python2.7/lib-tk/Tkinter.py", line 1470, in __call__
return self.func(*args)
File "/Users/lkloh/Library/Enthought/Canopy_64bit/User/lib/python2.7/site-packages/matplotlib/backends/backend_tkagg.py", line 413, in button_release_event
FigureCanvasBase.button_release_event(self, x, y, num, guiEvent=event)
File "/Users/lkloh/Library/Enthought/Canopy_64bit/User/lib/python2.7/site-packages/matplotlib/backend_bases.py", line 1808, in button_release_event
self.callbacks.process(s, event)
File "/Users/lkloh/Library/Enthought/Canopy_64bit/User/lib/python2.7/site-packages/matplotlib/cbook.py", line 525, in process
del self.callbacks[s][cid]
KeyError: 103
Do you have any idea how I can debug this/ what could be wrong? The error message does not point to anywhere in code I have personally written. I get the error message only after I close my GUI window, but I want to fix it even though it does not break the functionality of my code. 
The error is part of a very big program I am writing, so I cannot post all my code, but below is code I think is relevant:
def save(self, event):
        self.getSaveAxes()
        self.save_connect()
def getSaveAxes(self):
    saveFigure = figure(figsize=(8,1))
    saveFigure.clf()
    # size of save buttons
    rect_saveHeaders = [0.04,0.2,0.2,0.6]
    rect_saveHeadersFilterParams = [0.28,0.2,0.2,0.6]
    rect_saveHeadersOverride = [0.52,0.2,0.2,0.6]
    rect_saveQuit = [0.76,0.2,0.2,0.6]
    #initalize axes
    saveAxs = {}
    saveAxs['saveHeaders'] = saveFigure.add_axes(rect_saveHeaders)
    saveAxs['saveHeadersFilterParams'] = saveFigure.add_axes(rect_saveHeadersFilterParams)
    saveAxs['saveHeadersOverride'] = saveFigure.add_axes(rect_saveHeadersOverride)
    saveAxs['saveQuit'] = saveFigure.add_axes(rect_saveQuit)
    self.saveAxs = saveAxs
    self.save_connect()
    self.saveFigure = saveFigure
    show()
def save_connect(self):
    #set buttons
    self.bn_saveHeaders = Button(self.saveAxs['saveHeaders'], 'Save\nHeaders\nOnly')
    self.bn_saveHeadersFilterParams = Button(self.saveAxs['saveHeadersFilterParams'], 'Save Headers &\n Filter Parameters')
    self.bn_saveHeadersOverride = Button(self.saveAxs['saveHeadersOverride'], 'Save Headers &\nOverride Data')
    self.bn_saveQuit = Button(self.saveAxs['saveQuit'], 'Quit')
    #connect buttons to functions they trigger
    self.cid_saveHeaders = self.bn_saveHeaders.on_clicked(self.save_headers)
    self.cid_savedHeadersFilterParams = self.bn_saveHeadersFilterParams.on_clicked(self.save_headers_filterParams)
    self.cid_saveHeadersOverride = self.bn_saveHeadersOverride.on_clicked(self.save_headers_override)
    self.cid_saveQuit = self.bn_saveQuit.on_clicked(self.save_quit)
def save_quit(self, event):
    self.save_disconnect()
    close()