Numeric keypad keys in vi insert letters instead of numbers I'm new to vi. Actually I'm using it just to modify small text files. I've a serious and unusual, I think, problem with the numeric keypad, as follow:
I write vi IN and press enter. This make me access to the file named IN. Then I use arrow keys (or hjkl) to move the cursor through the file. Then I press i to activate the insert mode and write. Here comes the problem: numeric keypad doesn't work properly, since I get pqrstuvwxyl when I press 0123456789+ (,.-*/= still work).
I solved the problem on my own, but I'd like to know WHY my solution works.
I deselected the option the red arrow indicates in the following picture

This is italian, but the english version of the same window is here

But I don't recall enabling this but there it is.