Traceback (most recent call last):
  File "./generate_tiles.py", line 43, in <module>
    from mapnik import *
  File "/system/library/frameworks/python.framework/versions/2.5/lib/python2.5/site-packages/mapnik/__init__.py", line 31, in <module>
    from _mapnik import *
ImportError: dlopen(/system/library/frameworks/python.framework/versions/2.5/lib/python2.5/site-packages/mapnik/_mapnik.so, 10): Library not loaded: /sw/lib/libboost_filesystem-mt-1_34_1.dylib
  Referenced from: /usr/local/lib/libmapnik.dylib
  Reason: Incompatible library version: libmapnik.dylib requires version 1.34.0 or later, but libboost_filesystem-mt-1_34_1.dylib provides version 0.0.0