грешка при импортиране на модул на python

Използвам macports за инсталиране на различни модули. Като цяло това работи добре, но по-долу е грешка, която получавам и която не разрешавам лесно:

$ python
Python 2.6.6 (r266:84292, Feb 12 2011, 16:57:53) 
[GCC 4.2.1 (Apple Inc. build 5664)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import dns
>>> import opcode
>>> from dns import resolver
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/opt/local/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/dns/resolver.py", line 26, in <module>
    import dns.message
  File "/opt/local/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/dns/message.py", line 28, in <module>
    import dns.opcode
ImportError: No module named opcode

Възможно ли е това да е проблем с пътя?

>>> import sys
>>> sys.path
['', '/opt/local/Library/Frameworks/Python.framework/Versions/2.6/lib/python26.zip', '/opt/local/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6', '/opt/local/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/plat-darwin', '/opt/local/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/plat-mac', '/opt/local/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/plat-mac/lib-scriptpackages', '/opt/local/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/lib-tk', '/opt/local/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/lib-old', '/opt/local/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/lib-dynload', '/opt/local/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages', '/opt/local/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/setuptools-0.6c11-py2.6.egg-info']

$ cat /opt/local/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/dns/init.py [изрязани коментари] # init .py за DNS клас.

__version__ = '2.3.3'

import Type,Opcode,Status,Class
from Base import DnsRequest, DNSError
from Lib import DnsResult
from Base import *
from Lib import *
Error=DNSError
from lazy import *
Request = DnsRequest
Result = DnsResult

Благодаря предварително.