The printout of the extensions clearly indicates that all three of those extensions are present, yet the glewIsSupported() call is returning false. If I break it down to three separate checks, the first two work but GL_EXT_packed_depth_stencil does not register as present (despite being in the GL_EXTENSIONS printout).
GL_EXT_packed_depth_stencil is part of core OpenGL3.0. Are you sure that u have setup an opengl 3 context? how are u initializing the context? Are u using freeglut? let us know the details about it.
This extension has no functions, so try to use its tokens, and see if it works.
For about glew, I never used it so I can’t know. But try to check glewexperimental (http://glew.sourceforge.net/basic.html), or put less extension in glewIsSupported.
Simply removing the check “solved” the problem, since the extension works without incident. I still find it extremely strange that this was happening though and I’m curious what could have caused it.
I always figured that glewIsSupported was just parsing the string returned by glGetString, but maybe not?