Comment 1 for bug 865210

The traceback here is from slightly broken XPM, more complicated than just "foo". When submitting "foo", the error is:
File "/usr/lib/pymodules/python2.6/django/core/handlers/base.py" in get_response
  92. response = callback(request, *callback_args, **callback_kwargs)
File "/usr/lib/pymodules/python2.6/django/views/decorators/cache.py" in _wrapped_view_func
  44. response = view_func(request, *args, **kwargs)
File "/usr/lib/pymodules/python2.6/django/contrib/auth/decorators.py" in __call__
  78. return self.view_func(request, *args, **kwargs)
File "/srv/sc.ubuntu.com/production/software-center-agent/src/devportal/decorators.py" in inner_decorator
  83. return func(request, *args, **kwargs)
File "/srv/sc.ubuntu.com/production/software-center-agent/src/devportal/views.py" in application_update
  319. if form.is_valid():
File "/usr/lib/pymodules/python2.6/django/forms/forms.py" in is_valid
  120. return self.is_bound and not bool(self.errors)
File "/usr/lib/pymodules/python2.6/django/forms/forms.py" in _get_errors
  111. self.full_clean()
File "/usr/lib/pymodules/python2.6/django/forms/forms.py" in full_clean
  243. value = getattr(self, 'clean_%s' % name)()
File "/srv/sc.ubuntu.com/production/software-center-agent/src/softwarecenteragent/forms.py" in clean_icon_16
  96. return self._clean_icon(16)
File "/srv/sc.ubuntu.com/production/software-center-agent/src/softwarecenteragent/forms.py" in _clean_icon
  72. icon = Image.open(icon_file)
File "/usr/lib/python2.6/dist-packages/PIL/Image.py" in open
  1980. raise IOError("cannot identify image file")

IOError instead of ValueError.