easy_install installs 3.0.0c1 instead of 3.0.0 (final). I have duplicated this on a number of systems (OS X.5, Fedora 8, Ubuntu 9.04) with Python 2.5 and 2.6 and setuptools 0.6c9. Here's what easy_install is searching through (md5 numbers cutoff for readability):
python2.5 -m easy_install -v PyOpenGL
Searching for PyOpenGL
Reading http://pypi.python.org/simple/PyOpenGL/
Reading http://pyopengl.sourceforge.net
Reading https://sourceforge.net/project/showfiles.php?group_id=5988&package_id=6035
Reading http://pyopengl.sourceforge.net/ctypes/
Reading http://sourceforge.net/project/showfiles.php?group_id=5988
Found link: http://pypi.python.org/packages/source/P/PyOpenGL/PyOpenGL-3.0.0c1.zip#md5=
Found link: http://pypi.python.org/packages/2.4/P/PyOpenGL/PyOpenGL-3.0.0a5-py2.4.egg#
Found link: http://pypi.python.org/packages/source/P/PyOpenGL/PyOpenGL-3.0.0b6.zip#
Found link: http://pypi.python.org/packages/source/P/PyOpenGL/PyOpenGL-3.0.0c1.tar.gz#
Found link: http://pypi.python.org/packages/source/P/PyOpenGL/PyOpenGL-3.0.0a5.tar.gz#
Found link: http://pypi.python.org/packages/2.5/P/PyOpenGL/PyOpenGL-3.0.0a5-py2.5.egg#md5=
Found link: http://pypi.python.org/packages/source/P/PyOpenGL/PyOpenGL-3.0.0b6.tar.gz#md5=
Found link: http://pypi.python.org/packages/source/P/PyOpenGL/PyOpenGL-3.0.0a5.zip#md5=
Best match: PyOpenGL 3.0.0c1
Downloading http://pypi.python.org/packages/source/P/PyOpenGL/PyOpenGL-3.0.0c1.zip#md5=
etc.
Looks like easy_install is preferring PyPI uploads to SF downloads? SF is the official source for the package, apparently uploading a few versions of PyPI was an anti-robustness measure :( .