spi.py OSError (9) Bad File Descriptor

[kbknapp]

I have a function that is called when the navigation rocker is pushed to the right:

    def update_display(self, line):
        print('Updating display')
        lcd = self.__cad.lcd
        lcd.home()
        lcd.set_cursor(0, 1)
        lcd.write(' ' * pifacecad.lcd.LCD_WIDTH)
        lcd.set_cursor(0, 1)
        print('Writing {}'.format(line))
        lcd.write(line)

The switch event listener is set up like so:

# ROCKER_RIGHT = 7
listener = pifacecad.SwitchEventListener(chip=cad)
listener.register(ROCKER_RIGHT, pifacecad.IODIR_ON, platypi.next_option)
listener.activate()

On the fifth (5th) time I press the rocker right I ALWAYS get the following error:

Exception in thread Thread-1:
Traceback (most recent call last):
  File "/usr/lib/python3.4/threading.py", line 921, in _bootstrap_inner
    self.run()
  File "/usr/lib/python3.4/threading.py", line 869, in run
    self._target(*self._args, **self._kwargs)
  File "/usr/lib/python3.4/site-packages/pifacecommon/interrupts.py", line 339, in handle_events
    function(event)
  File "platypi.py", line 58, in next_option
    self.update_display(os.path.basename(self.__options[self.__index]))
  File "platypi.py", line 78, in update_display
    lcd.home()
  File "/usr/lib/python3.4/site-packages/pifacecad/lcd.py", line 251, in home
    self.send_command(LCD_RETURNHOME)  # set cursor position to zero
  File "/usr/lib/python3.4/site-packages/pifacecad/lcd.py", line 411, in send_command
    self.control_port.register_select_pin.value = 0
  File "/usr/lib/python3.4/site-packages/pifacecommon/mcp23s17.py", line 358, in value
    self.chip.write_bit(v, self.bit_num, self.address)
  File "/usr/lib/python3.4/site-packages/pifacecommon/mcp23s17.py", line 201, in write_bit
    old_byte = self.read(address)
  File "/usr/lib/python3.4/site-packages/pifacecommon/mcp23s17.py", line 143, in read
    return self._pyver_read(address)
  File "/usr/lib/python3.4/site-packages/pifacecommon/mcp23s17.py", line 147, in _py3read
    op, addr, data = self.spisend(bytes((ctrl_byte, address, 0)))
  File "/usr/lib/python3.4/site-packages/pifacecommon/spi.py", line 74, in spisend
    ioctl(self.fd, SPI_IOC_MESSAGE(1), transfer)
OSError: [Errno 9] Bad file descriptor

Just for curiosity sake, I added a print(self.fd) in spi.py which prints "4"