http://gentoo-wiki.com/HOWTO_XGL/Troubleshooting#GLX_EXT_texture_from_pixmap_is_missing
LD_LIBRARY_PATH=/usr/lib compiz --replace gconf & LD_PRELOAD=/usr/lib/opengl/xorg-x11/lib/libGL.so compiz --replace gconf
http://www.phoronix.com/forums/showthread.php?t=5947&page=6
This explains a little about the GLX_EXT_tecture_from_pixmap : http://bbs.archlinux.org/viewtopic.php?id=39120