problems with glx extension, using two graphic cards

[studix]

I have one of those vaio sz laptops which has two graphic cards, one being nvidia and the other intel. the problem is that my glx extension doesn't work when switching to intel card. I have "(WW) Warning, couldn't open module glx" in my Xorg log. when switching to nvidia it just works fine. I tried looking in /usr/lib/xorg/modules/extensions and the only glx related extension I found is libglx.so.169.09 which I am pretty sure is for nvidia driver. I tried ln -s libglx.so.169.09 libglx.so but after restarting X, its log says something about loading nvidia glx, and it doesn't work and I don't have glx support. I also tried eselect opengl set xorg-x11 and its like switching to x11-xorg opengl interface but nothing happens to /usr/lib/xorg/modules/extensions. I even tried re-emerging a newer version of mesa, but still the same problem: "Xlib: extension "GLX" missing on display ":0.0"."