Hi, Working on gst-plugins-gl ( <a href="http://diracvideo.org/git?p=gst-plugins-gl.git;a=summary">http://diracvideo.org/git?p=gst-plugins-gl.git;a=summary</a> , and the branch : <a href="http://diracvideo.org/git?p=gst-plugins-gl.git;a=shortlog;h=remove_gstfreeglut">http://diracvideo.org/git?p=gst-plugins-gl.git;a=shortlog;h=remove_gstfreeglut</a> ) , I am trying to resolve a bug about "ATI + fragment shader (from GLSL)  +  setlocale (from #include <locale.h>). Well, shaders are not working if  setlocale (LC_ALL, "");  is called. And no problem if   setlocale (LC_ALL, "C"); is called. I can see any relation bettween the 2 things. And setlocale (LC_ALL, ""); is called in gst_init. (cvs/gstreamer/gst/gst.c). I have spent a lot of time to find that the bug become when setlocale is called with arg "". Anyway, I have made a minimal test which only requires  freeglut (or glut) and have a graphic card which supports OpenGL and GLSL. I joined this test to this mail: ./test 0   give the wrong result:  red color in the window. ( setlocale (LC_ALL, "");  is called) ./test 1   give the right result:  yellow color in the window. ( setlocale (LC_ALL, "C"); is called) I have the bug on ubuntu intrepid (and Linux julien-desktop 2.6.27-9-generic #1 SMP Thu Nov 20 21:57:00 UTC 2008 i686 GNU/Linux) I join also my glxinfo output and my xorg.conf (I have little bit fired my xorg.conf  but I had same bug with the default xorg.conf) I have an ATI 9800 pro fglrxinfo: display: :0.0  screen: 0 OpenGL vendor string: ATI Technologies Inc. OpenGL renderer string: RADEON 9800 PRO OpenGL version string: 2.1.8087 Release (It seems there is no problem with an NVIDIA graphic card) setlocale doc: <a href="http://www.opengroup.org/onlinepubs/007908799/xsh/setlocale.html">http://www.opengroup.org/onlinepubs/007908799/xsh/setlocale.html</a> my config: echo $LANG fr_FR.UTF-8 So what do you think I can do ? Bug come from fr_FR.UTF-8 environnement ? Where should I report the problem ? Please try the test if you have an ATI and GLSL and linux. Sincerely Julien