Updates in ~/.vimrc not being reflected

Question

I am a new vim user. Before asking this question, I have gone through some of the similar questions asked at SO, such as : Q-1,Q-2,Q-3 and Q-4. None of them have solved my seemingly simple problem. It would be great if someone can help me understand what I am missing here.

Problem Description : I am working on a Ubuntu-12.04 32 bit system. No matter what I change in my ~/.vimrc file, it doesn't get reflected in how vim shows my files. Most recently, I added a few lines to change the status line of the vim to something more informative and color coded (copied from here). even after sourcing the ~/.vimrc using :so ~/.vimrc, none of the intended changes are implemented and the statusline stays the same as default. Given below is my ~/.vimrc file.

Please help me understand what am I am missing? The lines added for Statusline are towards the end of the ~/.vimrc file.

Thanks

My ~/.vimrc file :

" All system-wide defaults are set in $VIMRUNTIME/debian.vim (usually just
" /usr/share/vim/vimcurrent/debian.vim) and sourced by the call to :runtime
" you can find below.  If you wish to change any of those settings, you should
" do it in this file (/etc/vim/vimrc), since debian.vim will be overwritten
" everytime an upgrade of the vim packages is performed.  It is recommended to
" make changes after sourcing debian.vim since it alters the value of the
" 'compatible' option.

" This line should not be removed as it ensures that various options are
" properly set to work with the Vim-related packages available in Debian.
runtime! debian.vim

" Uncomment the next line to make Vim more Vi-compatible
" NOTE: debian.vim sets 'nocompatible'.  Setting 'compatible' changes numerous
" options, so any other options should be set AFTER setting 'compatible'.
"set compatible

" Vim5 and later versions support syntax highlighting. Uncommenting the
" following enables syntax highlighting by default.
if has("syntax")
  syntax on
endif

" If using a dark background within the editing area and syntax highlighting
" turn on this option as well
"set background=dark

" Uncomment the following to have Vim jump to the last position when
" reopening a file
"if has("autocmd")
"  au BufReadPost * if line("'\"") > 1 && line("'\"") <= line("$") | exe "normal! g'\"" | endif
"endif

" Uncomment the following to have Vim load indentation rules and plugins
" according to the detected filetype.
"if has("autocmd")
"  filetype plugin indent on
"endif

" The following are commented out as they cause vim to behave a lot
" differently from regular Vi. They are highly recommended though.
"set showcmd        " Show (partial) command in status line.
"set showmatch      " Show matching brackets.
"set ignorecase     " Do case insensitive matching
"set smartcase      " Do smart case matching
"set incsearch      " Incremental search
"set autowrite      " Automatically save before commands like :next and :make
"set hidden             " Hide buffers when they are abandoned
"set mouse=a        " Enable mouse usage (all modes)

" Source a global configuration file if available
if filereadable("/etc/vim/vimrc.local")
  source /etc/vim/vimrc.local
endif

map <F3> gT
map <F4> gt

syntax enable
syntax on
colorscheme darkblue 
"set autoindent
set cindent
set nu
set nowrap
set softtabstop=2
set shiftwidth=2
"set expandtab
autocmd BufWinLeave .* mkview
autocmd BufWinEnter .* silent loadview 
"set textwidth=60

"Lines added to change status line
"define 3 custom highlight groups
hi User1 ctermbg=green ctermfg=red   guibg=green guifg=red
hi User2 ctermbg=red   ctermfg=blue  guibg=red   guifg=blue
hi User3 ctermbg=blue  ctermfg=green guibg=blue  guifg=green

set statusline=
set statusline+=%1*  "switch to User1 highlight
set statusline+=%F   "full filename
set statusline+=%2*  "switch to User2 highlight
set statusline+=%y   "filetype
set statusline+=%3*  "switch to User3 highlight
set statusline+=%l   "line number
set statusline+=%*   "switch back to statusline highlight
set statusline+=%P   "percentage thru file

Answer 1

To have the status line visible at all times, just add set laststatus=2 to your .vimrc.

The standard value is laststatus=1, which only shows the status line if there are at least two visible windows (afaik, only when you're splitting the screen between two buffers)