Installation problem with new nvidia driver (440.82) and old cuda (8.0 and 9.0)

In order to run a paralleling computing program (VMD) in ubuntu 16.04 LTS using an GTX-780Ti and GTX970, a nvidia driver ( and cuda toolkit are like to be installed. The nvidia-smi command work fine immediately after 440.82 installation, but was failed and showed “NVIDIA-SMI has failed because it couldn’t communicate with the NVIDIA driver. Make sure that the latest NVIDIA driver is installed and running.” after installation of either cuda 8.0 ( or 9.0 ( without any error. Guidance and suggestions will be highly appreciated.