title: Django form error
body: <pre><code>class JobForm(forms.ModelForm):
      class Meta:
          model = models.Job
  </code></pre>
  
  <p>That was my form, now trying to save it will raise an exception, and trying to validate it just fails with no errors....</p>
  
  <pre><code>job = get_object_or_404(models.Job, pk=1)
  form = forms.JobForm(instance = job)
  try:
      form.save()
  except:
      print sys.exc_info()
  
  #=&gt;(&lt;type 'exceptions.AttributeError'&gt;, AttributeError("'JobForm' object has no attribute 'cleaned_data'",), &lt;traceback object at 0x1029dbb48&gt;)
  </code></pre>
  
  <p>Tried to validate it: </p>
  
  <pre><code>if form.is_valid():
      form.save()
  else:
      print 'error'
      print form.errors, len(form.errors)
  #=&gt; 'error' 
  #=&gt; 0
  </code></pre>
  
  <p>So the form isn't valid, but the there are no errors!
  Any idea?</p>