I ran into this issue while installing dblatex (0.2.10) from the most recent MacPorts tree today:

Traceback (most recent call last):
  File "/opt/local/bin/dblatex", line 16, in <module>
    from dbtexmf.dblatex import dblatex
ImportError: No module named dbtexmf.dblatex

I got past it by exporting PYTHONPATH=/opt/local/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages, but clearly this was not optimal. I was about to file a bug report about the issue but before I did that I read their new ticket guidelines which requested the full build log be included in the ticket.

In the build log was the solution. I would have missed it had my shell scrollback not been set to unlimited. Nestled a good 182 lines back in my buffer was this little message:

--->  Installing python26 @2.6.4_0+darwin
--->  Activating python26 @2.6.4_0+darwin

To fully complete your installation and make python 2.6 the default, please run

sudo port install python_select
sudo python_select python26

I did as instructed, and sure enough, dblatex started working! I just wanted to post this on the blog in case anyone else ran into this and missed it like I did.