Originally Posted by artem
At the driver install stage it's not safe to simply purge old modules as it can break the consistency of a system package manager (DEB or RPM).
Anyway NVIDIA software developers could indeed fix this problem by showing a big warning message if a kernel module from a previous driver version was detected in the system.
It is the same with xorg.conf, isn't it? the system package manager's configuration file is backed up and a new one is put there. And also other libraries are backed up before being substituted by the new ones. (I think for the --uninstall feature).