self.driver.quit() behaves differently for firefox and chrome

[SimSel]

I have self.driver.quit() in my teardown code. It works fine with Firefox where the browser closes as the test finishes. But with Chrome i see this error :

  File "C:\Repo\qa\Webdriver\QA\QA\RCY\placepetsad.py", line 81, in tearDown
    self.driver.quit()
  File "C:\Python27\lib\site-packages\selenium\webdriver\chrome\webdriver.py", line 78, in quit
    self.service.stop()
  File "C:\Python27\lib\site-packages\selenium\webdriver\chrome\service.py", line 94, in stop
    self.process.kill()
  File "C:\Python27\lib\subprocess.py", line 1016, in terminate
    _subprocess.TerminateProcess(self._handle, 1)
WindowsError: [Error 5] Access is denied

I am using Python bindings for webdriver and chrome Version 22.0.1229.94 m. Any idea why this might be ? Do i need to upgrade my chrome driver?

Thanks,
S