I'm on OS X.5 with Inkscape 0.45+devel, built Dec  8 2007
Whenever I try to use a filter get this:
The fantabulous lxml wrapper for libxml2 is required by inkex_lxml.py and therefore this extension. Please download the latest version from <http://cheeseshop.python.org/pypi/lxml/>.
and when i try to install it, it has an error and doesnt finnish and I can't figure out what is up. 
This is a copy of all the stuff from the terminal when i'm trying to instal lxml: 
easy_install lxml
Searching for lxml
Reading http://pypi.python.org/simple/lxml/
Reading http://codespeak.net/lxml
Best match: lxml 2.0alpha5
Downloading http://cheeseshop.python.org/packages/source/l/lxml/lxml-2.0alpha5.tar.gz
Processing lxml-2.0alpha5.tar.gz
Running lxml-2.0alpha5/setup.py -q bdist_egg --dist-dir /var/folders/H9/H9Jwuv1LGha040cHGswzMk+++TI/-Tmp-/easy_install-Dt6zmJ/lxml-2.0alpha5/egg-dist-tmp-Inbqr_
Building with Cython 0.9.6.9.
Building lxml version 2.0.alpha5.
warning: no previously-included files found matching 'doc/pyrex.txt'
warning: no previously-included files found matching 'src/lxml/etree.pxi'
src/lxml/lxml.etree.c:69:31:src/lxml/lxml.etree.c:69:31:  error: error: libxml/schematron.h: No such file or directory
libxml/schematron.h: No such file or directory
lipo: can't open input file: /var/folders/H9/H9Jwuv1LGha040cHGswzMk+++TI/-Tmp-//ccI51eCM.out (No such file or directory)
error: Setup script exited with error: command 'gcc' failed with exit status 1