title: pkg_resources.DistributionNotFound: distribute error on new Plone 4.3 instance
body: <p>I've just installed a new plone 4.3 instance in a folder which already contained 2 Plone 4.3 instance, which both work fine. When I try to run buildout I get this error:</p>
  
  <pre><code>Traceback (most recent call last):
    File "bin/buildout", line 17, in &lt;module&gt;
      import zc.buildout.buildout
    File "/usr/local/Plone4.3/buildout-cache/eggs/zc.buildout-1.7.1-py2.7.egg/zc/buildout/buildout.py", line 40, in &lt;module&gt;
      import zc.buildout.download
    File "/usr/local/Plone4.3/buildout-cache/eggs/zc.buildout-1.7.1-py2.7.egg/zc/buildout/download.py", line 20, in &lt;module&gt;
      from zc.buildout.easy_install import realpath
    File "/usr/local/Plone4.3/buildout-cache/eggs/zc.buildout-1.7.1-py2.7.egg/zc/buildout/easy_install.py", line 31, in &lt;module&gt;
      import setuptools.package_index
    File "/usr/local/Plone4.3/Python-2.7/lib/python2.7/site-packages/distribute-0.6.35-py2.7.egg/setuptools/package_index.py", line 158, in &lt;module&gt;
      sys.version[:3], require('distribute')[0].version
    File "/usr/local/Plone4.3/buildout-cache/eggs/setuptools-0.6c11-py2.7.egg/pkg_resources.py", line 666, in require
      continue    # try the next older version of project
    File "/usr/local/Plone4.3/buildout-cache/eggs/setuptools-0.6c11-py2.7.egg/pkg_resources.py", line 565, in resolve
  
  pkg_resources.DistributionNotFound: distribute
  </code></pre>
  
  <p>Google has failed me. Can anyone tell me how to resolve this error?</p>