We are finding that specular lighting is missing from opengl in our application. The problem spans the entire range of intel express integrated chipsets, both XP and Vista. It does not, however show up with other vendors' (AMD/NVidia) opengl implementations. Is that a known problem?
... and in a lightning turn-around of only 7 months, the driver team has found a bug in the OGL driver logic dealing with GL_SEPARATE_SPECULAR_COLOR. They don't have a fix as of yet, but they've identified the problem. I figured I'd keep this updated given the hectic progress on this issue so far...