Arch Linux

Description:
After upgrade to nvidia driver, X server fails to start.

Additional info:
* package version(s)
nvidia 331.20-1
nvidia-libgl 331.20-1
nvidia-utils 331.20-1

* config and/or log files etc.
no custom Xorg config
Xorg.0.log:
[ 2.734] (II) LoadModule: "glx"
[ 2.737] (II) Loading /usr/lib/xorg/modules/extensions/libglx.so
[ 2.890] (II) Module glx: vendor="NVIDIA Corporation"
[ 2.890] compiled for 4.0.2, module version = 1.0.0
[ 2.890] Module class: X.Org Server Extension
[ 2.890] (II) NVIDIA GLX Module 331.20 Wed Oct 30 17:36:48 PDT 2013
[ 2.890] Loading extension GLX
[ 2.891] (==) Matched nouveau as autoconfigured driver 0
[ 2.891] (==) Matched nvidia as autoconfigured driver 1
[ 2.891] (==) Matched nv as autoconfigured driver 2
[ 2.891] (==) Matched vesa as autoconfigured driver 3
[ 2.891] (==) Matched modesetting as autoconfigured driver 4
[ 2.891] (==) Matched fbdev as autoconfigured driver 5
[ 2.891] (==) Assigned the driver to the xf86ConfigLayout
[ 2.891] (II) LoadModule: "nouveau"
[ 2.893] (WW) Warning, couldn't open module nouveau
[ 2.893] (II) UnloadModule: "nouveau"
[ 2.893] (II) Unloading nouveau
[ 2.893] (EE) Failed to load module "nouveau" (module does not exist, 0)
[ 2.893] (II) LoadModule: "nvidia"
[ 2.894] (II) Loading /usr/lib/xorg/modules/drivers/nvidia_drv.so
[ 2.907] (II) Module nvidia: vendor="NVIDIA Corporation"
[ 2.907] compiled for 4.0.2, module version = 1.0.0
[ 2.907] Module class: X.Org Video Driver
[ 2.908] (II) LoadModule: "nv"
[ 2.909] (WW) Warning, couldn't open module nv
[ 2.909] (II) UnloadModule: "nv"
[ 2.909] (II) Unloading nv
[ 2.909] (EE) Failed to load module "nv" (module does not exist, 0)
[ 2.909] (II) LoadModule: "vesa"
[ 2.909] (WW) Warning, couldn't open module vesa
[ 2.909] (II) UnloadModule: "vesa"
[ 2.909] (II) Unloading vesa
[ 2.909] (EE) Failed to load module "vesa" (module does not exist, 0)
[ 2.909] (II) LoadModule: "modesetting"
[ 2.909] (WW) Warning, couldn't open module modesetting
[ 2.909] (II) UnloadModule: "modesetting"
[ 2.909] (II) Unloading modesetting
[ 2.909] (EE) Failed to load module "modesetting" (module does not exist, 0)
[ 2.909] (II) LoadModule: "fbdev"
[ 2.909] (WW) Warning, couldn't open module fbdev
[ 2.909] (II) UnloadModule: "fbdev"
[ 2.909] (II) Unloading fbdev
[ 2.909] (EE) Failed to load module "fbdev" (module does not exist, 0)
[ 2.909] (II) NVIDIA dlloader X Driver 331.20 Wed Oct 30 17:16:53 PDT 2013
[ 2.909] (II) NVIDIA Unified Driver for all Supported NVIDIA GPUs
[ 2.910] (++) using VT number 7

[ 2.913] (II) Loading sub module "fb"
[ 2.913] (II) LoadModule: "fb"
[ 2.913] (II) Loading /usr/lib/xorg/modules/libfb.so
[ 2.915] (II) Module fb: vendor="X.Org Foundation"
[ 2.915] compiled for 1.14.4, module version = 1.0.0
[ 2.915] ABI class: X.Org ANSI C Emulation, version 0.4
[ 2.915] (WW) Unresolved symbol: fbGetGCPrivateKey
[ 2.915] (II) Loading sub module "wfb"
[ 2.915] (II) LoadModule: "wfb"
[ 2.915] (II) Loading /usr/lib/xorg/modules/libwfb.so
[ 2.917] (II) Module wfb: vendor="X.Org Foundation"
[ 2.917] compiled for 1.14.4, module version = 1.0.0
[ 2.917] ABI class: X.Org ANSI C Emulation, version 0.4
[ 2.917] (II) Loading sub module "ramdac"
[ 2.917] (II) LoadModule: "ramdac"
[ 2.917] (II) Module "ramdac" already built-in
[ 2.920] (II) NVIDIA(0): Creating default Display subsection in Screen section
"Default Screen Section" for depth/fbbpp 24/32
[ 2.920] (==) NVIDIA(0): Depth 24, (==) framebuffer bpp 32
[ 2.920] (==) NVIDIA(0): RGB weight 888
[ 2.920] (==) NVIDIA(0): Default visual is TrueColor
[ 2.920] (==) NVIDIA(0): Using gamma correction (1.0, 1.0, 1.0)
[ 2.920] (**) NVIDIA(0): Enabling 2D acceleration
[ 2.922] (EE) NVIDIA(0): Failed to initialize the NVIDIA kernel module. Please see the
[ 2.922] (EE) NVIDIA(0): system's kernel log for additional error messages and
[ 2.922] (EE) NVIDIA(0): consult the NVIDIA README for details.
[ 2.922] (EE) NVIDIA(0): *** Aborting ***
[ 2.922] (EE) NVIDIA(0): Failing initialization of X screen 0
[ 2.922] (II) UnloadModule: "nvidia"
[ 2.922] (II) UnloadSubModule: "wfb"
[ 2.922] (II) UnloadSubModule: "fb"
[ 2.922] (EE) Screen(s) found, but none have a usable configuration.
[ 2.922] (EE)
Fatal server error:
[ 2.922] (EE) no screens found(EE)

lsmod:
nvidia 10573185 0
drm 238206 2 nvidia,vboxvideo
i2c_core 24164 3 drm,i2c_piix4,nvidia

Steps to reproduce:
# pacman -Syu
upgrades nvidia, nvidia-utils, nvidia-libgl from 325 to 331
# reboot
stuck at tty1
login as root
downgrade to nvidia 325
# pacman -U nvidia-325.15-11-x86_64.pkg.tar.xz nvidia-libgl-325.15-1-x86_64.pkg.tar.xz nvidia-utils-325.15-1-x86_64.pkg.tar.xz
# reboot
kde starts normally

Note:
I have two arch boxes. One box has the system partition is on a SATA2 SSD, the other box has it on an IDE spinning disk. 331 fails on the SSD and succeeds on the spinning disk. Both systems run KDE 4.11.3, linux 3.12.0-1 and systemd 208-2