In case anyone else needs help on solving this in the future, this is a 
solution to my problem when I have python2.7 altinstalled, 
matplotlib-1.0.0, ipython, and numpy installed using pip-2.7.

I was getting this error:
"NameError: global name 'lapack_lite' is not defined"

when using ipython -pylab then plotting something.

SOLUTION:
install lapack-devel and reinstall numpy using pip-2.7 ala:

 > pip-2.7 install numpy

It should then download the latest version from pypi and compile and 
install it properly.

Now, normally I would just use things in the repos in order to make it 
easier for me but one of my users requested a version of matplotlib and 
PyQt among other things that were not included in SL5 repos.