Vim is my favorite text editor when it come to work in terminal interface and Putty as my one and only one ssh client to connect to servers. And, if you use putty as ssh client and vim, you have noticed that numeric keypad keys will not work. Below, you will find a simple step to take to avoid that behave.
Before you login to ssh session, you have to change the configuration of the putty session.
Terminal> Features and check the Disable Application keypad mode