KDE Neon, after a fresh install hungs after a short time. some secconds to few minutes


I have performed a fresh Neon install .
I have a nvidia geoforce 660.

At this moment the Nouveau driver is installed.

After booting and starting session, in a short time, after moving the cursor, or doing somethin, not always with the same delay, the system hungs and I must to hard-reboot.

I think the blame can be on the graphics card driver. But I am no t sure.

Can any body point me in the right direction ?

Thanks in advanced