What's in your .vimrc file?
jyf1987: syntax oncolor zellnerset cursorlineset cursorcolumnset nuset autoindentset tabstop=4map <C-n> <ESC><ESC>:tabnew<CR>map <C-left> <ESC><ESC>:tabprev<CR>map <C-right> <ESC><ESC>:tabnext<CR>map <C-down> <ESC><ESC>:tabclose<CR