It appears I can reproduce this bug with the NV40. Starting Lucid with the external DVI-D connected and plymouth output mirrored it 'stops' with the plymouth splash screen as described previously.
Using Alt+SysReq+K to kill the processes on the current terminal (tty7 at this point) disk activity increases and Xorg restarts and presents the GDM greeter/log-in screen from where things progress.
I've not yet seen any similar freeze after logging in, but maybe DJR013 can suggest an application/action that is almost guaranteed to produce one so I can test?
It appears I can reproduce this bug with the NV40. Starting Lucid with the external DVI-D connected and plymouth output mirrored it 'stops' with the plymouth splash screen as described previously.
Using Alt+SysReq+K to kill the processes on the current terminal (tty7 at this point) disk activity increases and Xorg restarts and presents the GDM greeter/log-in screen from where things progress.
I've not yet seen any similar freeze after logging in, but maybe DJR013 can suggest an application/action that is almost guaranteed to produce one so I can test?