Maybe i'm wrong but akmod Nvidia don't seems to work with fedora 17.
I have sucessfully installed the Nvidia binaries thus.
I met a bug too when i tried to blacklist nouveau with dracut Laptop shuted down and didn't boot when i started it again.
(What i have done is to change /etc/default/grub in adding blacklist=nouveau and rebuild the grub2 again. )
Thank you guys.
Have a nice day.