Comment 5 for bug 37598

Fast reply notwithstanding, I was also rather tired last night when I replied and didn't take into account that glxinfo isn't actually linked with libdrm at all, but is rather pulling it in as a transitive dependency from libGL.

Can you check:

dpkg -l libgl1-mesa (should be 6.4.1-0ubuntu7 on dapper)
ldd /usr/lib/libGL.so.1 | grep drm
dpkg -S libGL.so.1

Also, which architecture is this running on, and are you using any non-free OpenGL drivers (like nvidia-glx, or xorg-driver-fglrx)?