same problem here: kubuntu karmic with 2.6.31-15 and nvidia 185 (current packages). going back to 2.6.31-14 kernel solved the problem for me.
I debugged the issue with strace: kdm doesn't crash, nor does the xserver. the problem is that X does open("/dev/nvidia0") and that takes about 15 seconds for some reason. kdm then thinks "starting X server takes too long, something must be wrong" and terminates the X server (and tries to start a failsafe one). when you look at the laptop screen (my case: lenovo T61 with nvs 140 quadro chip), the screen goes black when X is started, and it takes maybe 10 seconds till the nvidia logo appears. normaly the nvidia logo appears within a few seconds. in syslog you can see these messages: Nov 30 15:32:12 yomigaeri kdm[6476]: X server startup timeout, terminating Nov 30 15:32:15 yomigaeri kdm[6476]: X server died during startup Nov 30 15:32:15 yomigaeri kdm[6476]: Failed to start X server. Starting failsafe X server. so you know kdm stopped X server because it took too long to start. in my case X was started 15:31:56, and in strace there was a gap from :57 to :10 or so when open("/dev/nvidia0") was done. the kernel/dmesg doesn't have any error message from nvidia driver or similar. -- kdm fails to start/restart (but gdm does properly) in kubuntu karmic 64 bits and nvidia driver 185 https://bugs.launchpad.net/bugs/477066 You received this bug notification because you are a member of Ubuntu-X, which is subscribed to nvidia-graphics-drivers-180 in ubuntu. _______________________________________________ Mailing list: https://launchpad.net/~ubuntu-x-swat Post to : ubuntu-x-swat@lists.launchpad.net Unsubscribe : https://launchpad.net/~ubuntu-x-swat More help : https://help.launchpad.net/ListHelp