Arrow Key In Vi Showing A B C D

[Update: After some discussion with my friends.  The following only true for Ubuntu Desktop version.  By default, Ubuntu Server version installs full version of "vi". 2010.09.16 1538]

If you are using Vi text editor in Ubuntu and found that entering arrow key (up, down, left and right) resulting the letter A, B, C and D.   That's because by default, Ubuntu install "vim.tiny" instead of the full version "vim".

To solve it, it's easy, just install the full version "vim"
sudo apt-get install vim