Trouble installing psycopg2

Hi, I'm trying to install psycopg2 on a Centos 5, 64-bit machine. I have
both 2.4 and 2.7 Python versions on this machine. I attempted to install
using
easy-install2.7 psycopg2

The install is not working. (I can't import psycopg2 in a python 2.7
session). yum doesn't list it as installed. But when I try to install it
again, easy_install responds that it's already installed. That's the short
version of the problem, more details below that may or may not be helpful.

Thanks,
LT

At first, easy-install2.7 psycopg2 gave me similar errors to what's
described on this page:
http://stackoverflow.com/questions/9600111/install-pg-config-in-centos-5-5-without-yum(something
to do with pg_config not found). So I followed the advice of
installing devel

yum install postgresql84-devel

...succeeded.

Then, I "easy-install2.7 psycopg2" again. In fact I piped the output to a
file and got what I have below, but it also flashed up an error message
which didn't get into this file and I can't see on the history. But from
that second that I saw it, I know it had __FILE__ in it. Now I'm in this
installed/but not installed kind of limbo.
...
Excluding Packages in global exclude list
Finished
Available Packages
python-psycopg2.x86_64 2.0.14-2.el5
epel
python-psycopg2-doc.x86_64 2.0.14-2.el5
epel
python-psycopg2-zope.x86_64 2.0.14-2.el5
epel
root(at)server [/opt/bin]# easy_install-2.7 psycopg2
Searching for psycopg2
Searching for psycopg2
Reading http://pypi.python.org/simple/psycopg2/
Reading http://initd.org/projects/psycopg2
Best match: psycopg2 2.5.1
Downloading
https://pypi.python.org/packages/source/p/psycopg2/psycopg2-2.5.1
.tar.gz#md5=1b433f83d50d1bc61e09026e906d84c7
Processing psycopg2-2.5.1.tar.gz
Writing /tmp/easy_install-UYNn1g/psycopg2-2.5.1/setup.cfg
Running psycopg2-2.5.1/setup.py -q bdist_egg --dist-dir
/tmp/easy_install-UYN
n1g/psycopg2-2.5.1/egg-dist-tmp-FLKSTs
Adding psycopg2 2.5.1 to easy-install.pth file

Installed
/usr/local/lib/python2.7/site-packages/psycopg2-2.5.1-py2.7-linux-x
86_64.egg
Processing dependencies for psycopg2
Finished processing dependencies for psycopg2