Just out of the blue, for no apparent reason, tuxracer didnt work today. Complained about not being able to find libGL.so.1. I tried re-emerging nvidia-kernel and nvidia-glx but didnt help. So I dug around in /usr/lib a bit and found that /usr/lib/libGL.so.1 points to a directory "/usr/lib/opengl//lib/". So I dug around there too a bit. Finally, I linked /usr/lib/libGL.so.1 to /usr/lib/opengl/nvidia/libGL.so.1 and that helped since tuxracer started bitching about another file libGLcore.so.1. I created a symlink /usr/lib/libGLcore.so.1 and pointed it to /usr/lib/opengl/nvidia/libGLcore.so.1 and tuxracer ran just fine after that. So I guess there's something that breaks these symlinks. Probably doing emerge nvidia-glx/nvidia-kernel. There was another guy on #gentoo today (yesterday actually, been up all night) who had the same problem.
next time, just run `opengl-upadte nvidia` reopen this bug if you can come up with instructions on how to reproduce this behavior