fglrx-updates 2:8.982-0ubuntu0.1: DRI initialization failed (with 3.2.0-31 kernel)

After updating my Ubuntu 12.04 (amd64) to kernel 3.2.0-31 and fglrx-updates 2:8.982-0ubuntu0.1 my X11 is *not* accelerated any more (e.g. no desktop/windows effects). It feels very sluggish.

In /var/log/Xorg.0.log I found the following:

[ 33.043] (==) fglrx(0): Buffer Tiling is ON
[ 33.044] (II) Loading sub module "fglrxdrm"
[ 33.044] (II) LoadModule: "fglrxdrm"
[ 33.044] (II) Loading /usr/lib/x86_64-linux-gnu/xorg/extra-modules/extra-modules.dpkg-tmp/modules/linux/libfglrxdrm.so
[ 33.044] (II) Module fglrxdrm: vendor="FireGL - AMD Technologies Inc."
[ 33.044] compiled for 1.4.99.906, module version = 8.98.2
[ 33.045] ukiDynamicMajor: failed to open /proc/ati/major
[ 33.045] ukiDynamicMajor: failed to open /proc/ati/major
[ 33.045] (**) fglrx(0): NoAccel = NO
[ 33.045] (**) fglrx(0): AMD 2D Acceleration Architecture enabled
[ 33.045] (--) fglrx(0): Chipset: "ATI Radeon HD 5450 " (Chipset = 0x68f9)
[...]
[ 33.968] (EE) fglrx(0): atiddxDriScreenInit failed, GPS not been initialized.
[ 33.968] (WW) fglrx(0): ***********************************************************
[ 33.968] (WW) fglrx(0): * DRI initialization failed *
[ 33.968] (WW) fglrx(0): * kernel module (fglrx.ko) may be missing or incompatible *
[ 33.968] (WW) fglrx(0): * 2D and 3D acceleration disabled *
[ 33.968] (WW) fglrx(0): ***********************************************************
[...]
[ 34.949] (EE) fglrx(0): XMM failed to open CMMQS connection.(EE) fglrx(0):
[ 34.949] (EE) fglrx(0): XMM failed to initialize
[...]
[ 37.906] [glesx] __glESXExtensionInit: No GL ES2.0 capable screen found!
[ 37.918] (II) AIGLX: Screen 0 is not DRI capable