most recent install instruction for Mac OS

Can someone point me to up to date installation instructions for Mac OS (10.6.4, python 2.6.4)?

Every route I pursue hits a dead end.
- if I install from dmg files on the matplotlib, it is not visible to my python installation (I think it installs to the OSX native python).
- if I install via easy_install or pip, then I get an error (previously emailed about) saying that numpy is incorrectly installed (Numpy tests pass)
- if I try to follow the instructions on, I get errors such as:


tar: Unrecognized archive format: Inappropriate file type or format
tar: Error exit delayed from previous errors.
make: *** [zlib] Error 1

Ages ago I successfully installed on my laptop but I do not seem to be able to repeat the feat on my desktop.
Any help appreciated.