I have Linux Mint 12 Gnome desktop, everything was normal yesterday. I shut my PC down yesterday and went to sleep, I turned it on today, and see what happened

You see how everything is messed up? The desktop normally should look like this. I tried to switch between the Gnome classic and the Gnome classic (no effects), but it make no difference, there are the only themes that i have. When I press restart, it logs me out, it does not restart. I shut it down and turned it on again but there's no difference.
EDIT
I have been told that this is Gnome Fallback mode, which is forced on you when your graphics card driver doesn't have the needed 3D acceleration support. This happens mostly with discrete graphics cards with proprietary drivers.
the output of inxi -Gxc 0 is
Graphics: Card: nVidia G86 [GeForce 8500 GT] bus-ID: 01:00.0
X.Org 1.10.4 drivers nouveau unloaded: fbdev,vesa Resolution 1024x768@60.0hz
GLX Renderer Gallium 0.4 on NV86 GLX Version 2.1 Mesa 7.11 Direct Rendering Yes
Update
i updated nvidia, now the output is this
Graphics: Card: nVidia G86 [GeForce 8500 GT] bus-ID: 01:00.0
X.Org 1.10.4 drivers nvidia unloaded: fbdev,vesa,nouveau Resolution 1024x768@50.0hz
GLX Renderer GeForce 8500 GT/PCIe/SSE2 GLX Version 3.3.0 NVIDIA 295.33 Direct Rendering Yes
the error is not fixed