first of all thanks for your quickly replies.
I'm sorry to have post a wrong log. Anyway error was the same except for 22 instead 18.
Talking about yum it was correctly installed and configured and enabled with rpmfusion repos.
After installation via yum my displayed screen was smaller in terms of area displayed. I have a 15.4" monitor but used area was about 2/3 of the available. In other words I'd got a black area on right taking about 1/3 of the monitor. There was also a bad resolution.
Installing, either via yum and package "NVIDIA-Linux-x86-173.14.18-pkg1.run", I followed step by step and very carefully instructions reported on site http://rpmfusion.org/Howto/nVidia
. As result I had a black screen with a blinking cursor on top left.
As usually thanks in advance for any help.