Just as an update and to close this thread, it seems that the reason why the drivers installed first time and then not the second was due to not installing the kernal sources when I installed Mandrake.
So a small word of advice to fellow newcomers to linux is to MAKE SURE you install the kernal sources when you install the O/S. Then it's a simple matter of starting without X then login in as root, then;
tar zxf NDIVIA_k*
tar zxf NVIDIA_G*
Then you need to alter the device "nv" part of your XConfig to read device "nvidia".
And that (touch wood) is that