Comment 3 for bug 1294163

Unfortunately, the new nvidia driver 331.20-0ubuntu0.0.2 is not working with KDE.
Logging-in is possible but then a black screen is shown, but the xserver is not crashed.

In Xorg.log there is an error with acpi; log attached

[ 11.962] (II) NVIDIA(0): ACPI: failed to connect to the ACPI event daemon; the daemon
[ 11.962] (II) NVIDIA(0): may not be running or the "AcpidSocketPath" X
[ 11.962] (II) NVIDIA(0): configuration option may not be set correctly. When the
[ 11.962] (II) NVIDIA(0): ACPI event daemon is available, the NVIDIA X driver will
[ 11.962] (II) NVIDIA(0): try to use it to receive ACPI event notifications. For
[ 11.962] (II) NVIDIA(0): details, please see the "ConnectToAcpid" and
[ 11.962] (II) NVIDIA(0): "AcpidSocketPath" X configuration options in Appendix B: X
[ 11.962] (II) NVIDIA(0): Config Options in the README.

Using the old nvidia 304 driver, I'm getting the following error at loading the nvidia module;

[ 5.543571] nvidia: module verification failed: signature and/or required key missing - tainting kernel
[ 5.544024] nvidia: Unknown symbol acpi_os_wait_events_complete (err 0)

Maybe there is an incompatibility with the acpid or with the acpi kernel functions?

Best regards, Bernhard