Are you sure you didn't deactivate use site ? (by turning site.ENABLE_USER_SITE off)

Please check its value:

  >>> import site
  >>> site.ENABLE_USER_SITE 
  True


Pathes look fine on my Mac : 

Python 2.7b2+ (trunk:81228, May 16 2010, 14:42:34) 
[GCC 4.0.1 (Apple Inc. build 5490)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import sys
>>> sys.path
['', '/usr/local/lib/python2.7/site-packages/pip-0.6.1-py2.7.egg', '/usr/local/lib/python2.7/site-packages/distribute-0.6.11dev-py2.7.egg', '/usr/local/lib/python27.zip', '/MacDev/svn.python.org/python-trunk/Lib', '/MacDev/svn.python.org/python-trunk/Lib/plat-darwin', '/MacDev/svn.python.org/python-trunk/Lib/plat-mac', '/MacDev/svn.python.org/python-trunk/Lib/plat-mac/lib-scriptpackages', '/MacDev/svn.python.org/python-trunk/Lib/lib-tk', '/MacDev/svn.python.org/python-trunk/Lib/lib-old', '/MacDev/svn.python.org/python-trunk/build/lib.macosx-10.4-i386-2.7', '/Users/tarek/.local/lib/python/2.7/site-packages', '/usr/local/lib/python2.7/site-packages']


If you still have the issue, you need to trace python load in site.py, where all the paths are added, by printing them out for example, and using the -v flag