tips on keep certain packages while updating (i.e. nvidia drivers)

Hi: I have a little problem when updating my nvidia system: usually new kernel updates pushes the matching kmod-nvidia package to be updated too (which is nice) but in the process removes old ones, tipically the ones the system is using at that moment. I'm not a fan of rebooting except when absolutely need and this behavior makes mad gnome-shell when I restart it (it eats lots of memory due to memory leaks from hell). Do you have any tip to keep just certain packages not removed when updating? using yum -x or /etc/yum/protect.d/* seems no to work for this. Thanks in advance. -- Ismael Olea http://olea.org/diario/