OSX 10.5 has a broken poll, this is an already known issue as I noticed
there's even a HAVE_BROKEN_POLL option that is in the source:
http://mail.python.org/pipermail/python-checkins/2006-April/051710.html

However, this run-time check apparently does not work, as I continue to
get socket errors related to the broken poll (On *any* version of Python
I compile from 2.4 through 2.6) unless I recompile Python and manually
comment out HAVE_POLL like the first line of Apple's Python patch here:
http://www.opensource.apple.com/darwinsource/10.5.6/python-30.1.2/fix/pyconfig.ed

Further, I think its quite likely that other bugs being submitted all
over the place from users running MacPorts on OSX are misdiagnosing this
bug as they believe its related to other software, when it is in fact
specific to custom compiles (MacPorts included) of Python. This bug
usually manifests itself as a Socket 35 error like so:
http://bugs.python.org/issue1085
http://www.cherrypy.org/ticket/598

This issue was diagnosed for me by Phil Jenvey, who believes that all
versions of OSX to date have had a broken poll (which reflects my paste
experience with this socket 35 bug as well).

I'm not sure of the most appropriate fix, I've submitted a bug to
MacPorts as well with the recommendation that for now they apply a patch
to undef HAVE_POLL, as Apple does.