title: RuntimeWarning: compiletime version 2.6 of module 'lxml.etree' does not match runtime version 2.7
body: <p>I am using python 2.7 and I am trying to use <a href="http://lxml.de/" rel="nofollow noreferrer">lxml</a>, but when I try using lxml.etree, I get this error:</p>
  
  <blockquote>
    <p>RuntimeWarning: compiletime version 2.6 of module 'lxml.etree' does not match runtime version 2.7</p>
  </blockquote>
  
  <p>And then this error:</p>
  
  <blockquote>
    <p>File "lxml.etree.pyx", line 123, in init lxml.etree (src/lxml/lxml.etree.c:160385)
    TypeError: encode() argument 1 must be string without null bytes, not unicode</p>
  </blockquote>
  
  <p>I have tried installing using easy_install and using pip</p>
  
  <p>After installing, I see this message:</p>
  
  <blockquote>
    <p>Installed /usr/lib/python2.6/site-packages/lxml-2.3.3-py2.6-linux-x86_64.egg</p>
  </blockquote>