Comment 7 for bug 510390

root@ix:/usr/lib # dpkg -l | grep nvidia
ii nvidia-173-modaliases 173.14.22-0ubuntu6 Modaliases for the NVIDIA binary X.Org drive
ii nvidia-96-modaliases 96.43.14-0ubuntu6 Modaliases for the NVIDIA binary X.Org drive
ii nvidia-common 0.2.18 Find obsolete NVIDIA drivers
ii nvidia-current 190.53-0ubuntu8 NVIDIA binary Xorg driver, kernel module and
ii nvidia-current-modaliases 190.53-0ubuntu8 Modaliases for the NVIDIA binary X.Org drive
pc nvidia-glx 1:1.0.9639+2.6.22.4-14.9 NVIDIA binary XFree86 4.x/X.Org driver
ii nvidia-settings 190.53-0ubuntu1 Tool of configuring the NVIDIA graphics driv

mplayer still does work:

[vdpau] Could not open dynamic library libvdpau.so.1

root@ix:/usr/lib # find /usr/lib -name libvdpau.so.1 -ls
root@ix:/usr/lib # find /usr/lib -name \*nvidia\*.so\* -ls
36798466 0 lrwxrwxrwx 1 root root 38 Jan 23 20:36 /usr/lib/vdpau/libvdpau_nvidia.so.1 -> /etc/alternatives/libvdpau_nvidia.so.1
13959205 0 lrwxrwxrwx 1 root root 23 Jan 22 10:48 /usr/lib/nvidia-current/libnvidia-cfg.so.1 -> libnvidia-cfg.so.190.53
13893650 8 -rw-r--r-- 1 root root 4484 Jan 21 21:45 /usr/lib/nvidia-current/libnvidia-tls.so.190.53
34816035 0 lrwxrwxrwx 1 root root 20 Jan 22 10:48 /usr/lib/nvidia-current/vdpau/libvdpau_nvidia.so -> libvdpau_nvidia.so.1
34816031 0 lrwxrwxrwx 1 root root 25 Jan 22 10:48 /usr/lib/nvidia-current/vdpau/libvdpau_nvidia.so.1 -> libvdpau_nvidia.so.190.53
34816032 1444 -rw-r--r-- 1 root root 1472992 Jan 21 21:45 /usr/lib/nvidia-current/vdpau/libvdpau_nvidia.so.190.53
13893649 116 -rw-r--r-- 1 root root 118168 Jan 21 21:45 /usr/lib/nvidia-current/libnvidia-cfg.so.190.53
7585794 8 -rw-r--r-- 1 root root 4656 Jan 21 21:45 /usr/lib/nvidia-current/tls/libnvidia-tls.so.190.53
7586124 0 lrwxrwxrwx 1 root root 23 Jan 14 01:13 /usr/lib/nvidia-current/tls/libnvidia-tls.so.1 -> libnvidia-tls.so.190.53
13959174 0 lrwxrwxrwx 1 root root 23 Jan 22 10:48 /usr/lib/nvidia-current/libnvidia-tls.so.1 -> libnvidia-tls.so.190.53
8208404 4192 -rw-r--r-- 1 root root 4288040 Jan 21 21:45 /usr/lib/nvidia-current/xorg/nvidia_drv.so
13959203 0 lrwxrwxrwx 1 root root 18 Jan 22 10:48 /usr/lib/nvidia-current/libnvidia-cfg.so -> libnvidia-cfg.so.1
6602854 0 lrwxrwxrwx 1 root root 28 Jan 23 20:36 /usr/lib/xorg/modules/drivers/nvidia_drv.so -> /etc/alternatives/nvidia_drv
16024690 112 -rw-r--r-- 1 root root 108168 Jun 2 2009 /usr/lib/directfb-1.2-0/gfxdrivers/libdirectfb_nvidia.so
6652338 20 -rw-r--r-- 1 root root 17936 May 12 2009 /usr/lib/sensors-applet/plugins/libnvidia.so

i also needed to add libvdpau1, it's fine now.

So nvidia-185-libvdpau was the culprit, it should either be fixed (the alternative) or conflicts