マジックコメントでfiletypeを変更できない件

.vimrc

set nocompatible               " be iMproved
filetype off                   " required!

set rtp+=~/.vim/bundle/vundle/
call vundle#rc()

" let Vundle manage Vundle
" required! 
Bundle 'gmarik/vundle'

Bundle 'unite.vim'
Bundle 'snipMate'
Bundle 'Shougo/neocomplcache'

Bundle 'rails.vim'
Bundle 'fugitive.vim'
Bundle 'Shougo/vimfiler'

Bundle 'https://github.com/cakebaker/scss-syntax.vim.git'

Bundle 'vim-coffee-script'

"================================================================================
" ruler, statusline
"================================================================================
set number

"ステータスラインを常に表示
set laststatus=2
" ステータスラインの表示
set statusline=%<[%n]%m%r%h%w%{'['.(&fenc!=''?&fenc:&enc).':'.&ff}%{']'}%y%{fugitive#statusline()}\ %F%=%l,%c%V%8P
"set statusline=%<[%n]%m%r%h%w%{'['.(&fenc!=''?&fenc:&enc).':'.&ff}%{']'}%y

if &term =~ "screen"
  " screen Buffer 切り替えで screen にファイル名を表示
  autocmd BufEnter * if bufname("") !~ "^\[A-Za-z0-9\]*://" | silent! exe '!echo -n "kv:%\\"' | endif
endif
"================================================================================
" syntax and colors
"================================================================================
syntax enable
colorscheme darkblue

" We know xterm-debian is a color terminal
if &term =~ "xterm-debian" || &term =~ "xterm-xfree86" || &term =~ "xterm-256color"
 set t_Co=16
 set t_Sf=[3%dm
 set t_Sb=[4%dm
endif

"タブ文字の表示
set list
set listchars=tab:>-,trail:\ 

"括弧入力時の対応する括弧を表示
set showmatch

" Don't wrap words by default
set textwidth=0

set t_Co=16
set t_Sf=[3%dm
set t_Sb=[4%dm

if !has('win32')
  " 補完候補色
  hi Pmenu ctermbg=8
  hi PmenuSel ctermbg=12
  hi PmenuSbar ctermbg=0
endif

if !has('macunix')
  highlight Visual ctermbg=0
else
  highlight Visual ctermbg=8
end

highlight SpecialKey ctermbg=2
highlight MatchParen cterm=none ctermbg=15 ctermfg=0
highlight Search ctermbg=5 ctermfg=0

" highlight 上書き
autocmd VimEnter,WinEnter * highlight SpecialKey ctermbg=0
autocmd VimEnter,WinEnter * highlight PmenuSel ctermbg=12

" trailing whitespace
" highlight ExtraWhitespace ctermbg=red guibg=red
" match ExtraWhitespace /\s\+$/
" autocmd BufWinEnter * match ExtraWhitespace /\s\+$/
" autocmd InsertEnter * match ExtraWhitespace /\s\+\%#\@<!$/
" autocmd InsertLeave * match ExtraWhitespace /\s\+$/
" autocmd BufWinLeave * call clearmatches()
" Show trailing whitepace and spaces before a tab:
autocmd Syntax * syn match ExtraWhitespace /\s\+$\| \+\ze\t/

"================================================================================
" tabstop and indents
"================================================================================
if has("autocmd")
  filetype plugin on
  filetype indent on
  " これらのftではインデントを無効に
  " autocmd FileType php filetype indent off
  " autocmd FileType xhtml :set indentexpr=
endif

" タブ幅の設定
set expandtab
set tabstop=2
set softtabstop=2
set shiftwidth=2
set modelines=0

set smartindent
"================================================================================
" search
"================================================================================
" 検索文字列が小文字の場合は大文字小文字を区別なく検索する
set ignorecase
" 検索文字列に大文字が含まれている場合は区別して検索する
set smartcase
" 検索時に最後まで行ったら最初に戻る
set wrapscan
" 検索で色をつける
set hlsearch
" 検索文字列入力時に順次対象文字列にヒットさせない
set noincsearch
" インクリメンタル検索
set incsearch
" gh で hilight を消す
nnoremap <silent> gh :let @/=''<CR>

" 検索レジストリに入ってる文字で現在のファイルを検索し、quickfix で開く
nnoremap <unique> g/ :exec ':vimgrep /' . getreg('/') . '/j %\|cwin'<CR>
" G/ ではすべてのバッファ
" nnoremap <unique> G/ :silent exec ':cexpr "" \| :bufdo vimgrepadd /' . getreg('/') . '/j %'<CR>\|:silent cwin<CR>

" バッファから検索
function! Bgrep(word)
  cexpr '' " quickfix を空に
  silent exec ':bufdo | try | vimgrepadd ' . a:word . ' % | catch | endtry'
  silent cwin
endfunction
command! -nargs=1 Bgrep :call Bgrep(<f-args>)

" :grepで組み込みのgrepを使う
set grepprg=internal
"================================================================================
" editing
"================================================================================
" Insert モード抜けたら nopaste
autocmd InsertLeave * set nopaste

" Visualモードのpで上書きされたテキストをレジスタに入れない
vnoremap p "_c<C-r>"<ESC>

" more powerful backspacing
set backspace=indent,eol,start

" http://d.hatena.ne.jp/edvakf/20100512/1273697666
" nnoremap sc :call system("pbcopy", @")
" copy to clipboard
if has("unix") && match(system("uname"),'Darwin') != -1 " mac
  " http://www.mail-archive.com/vim-latex-devel@lists.sourceforge.net/msg00773.html
  nnoremap fc :call system("pbcopy", @")<CR>
  nnoremap fp :r! pbpaste<CR>
elseif has('win32unix') " cygwin
  nnoremap fc :call system("putclip", @")<CR>
  nnoremap fp :r! getclip<CR>
endif

" Gスクロールが遅い件の対応
" set timeoutlen=400

" C-CでESC
inoremap <C-C> <ESC>
"================================================================================
" cursor moving
"================================================================================
"表示行単位で行移動する
nnoremap j gj
nnoremap k gk
vnoremap j gj
vnoremap k gk

" カーソル移動時の全角半角の判定をうまいことやる
set ambiwidth=double 

" 前回終了したカーソル行に移動
autocmd BufReadPost * if line("'\"") > 0 && line("'\"") <= line("$") | exe "normal g`\"" | endif
"================================================================================
" completion
"================================================================================
" 辞書ファイルからの単語補間
set complete+=k

" コマンドライン補間をシェルっぽく
set wildmode=list:longest

" Suffixes that get lower priority when doing tab completion for filenames.
" These are files we are not likely to want to edit or read.
set suffixes=.bak,~,.swp,.o,.info,.aux,.log,.dvi,.bbl,.blg,.brf,.cb,.ind,.idx,.ilg,.inx,.out,.toc

" Bundle 'Shougo/neocomplcache'
let g:neocomplcache_enable_at_startup = 1 
let g:neocomplcache_enable_auto_select = 1 

" Use smartcase.
let g:neocomplcache_enable_smart_case = 1
" Use camel case completion.
let g:neocomplcache_enable_camel_case_completion = 1
" Use underbar completion.
let g:neocomplcache_enable_underbar_completion = 1
" Set minimum syntax keyword length.
let g:neocomplcache_min_syntax_length = 3 

imap <expr><TAB> neocomplcache#sources#snippets_complete#expandable() ? "\<Plug>(neocomplcache_snippets_expand)" : pumvisible() ? "\<C-n>" : "\<TAB>" 
" <CR>: close popup and save indent.
" inoremap <expr><CR>  neocomplcache#smart_close_popup() . (&indentexpr != '' " ? "\<C-f>\<CR>X\<BS>":"\<CR>")
" <TAB>: completion.
inoremap <expr><TAB>  pumvisible() ? "\<C-n>" : "\<TAB>"
" <C-h>, <BS>: close popup and delete backword char.
inoremap <expr><C-h> neocomplcache#smart_close_popup()."\<C-h>"
inoremap <expr><BS> neocomplcache#smart_close_popup()."\<C-h>"
inoremap <expr><C-y>  neocomplcache#close_popup()
"================================================================================
" buffers
"================================================================================
" バッファが編集中でもその他のファイルを開けるように
set hidden
" 外部のエディタで編集中のファイルが変更されたら自動で読み直す
set autoread

"================================================================================
" tabs
"================================================================================
nmap tc :tabe<CR>
nmap te :tabe 
nmap to :tabe 
nmap tn :tabnext<CR>
nmap tp :tabNext<CR>
nmap td :tabclose<CR>

"================================================================================
" ruby
"================================================================================
" Bundle 'rails.vim'
autocmd BufNewFile,BufRead app/**/*.rhtml set fenc=utf-8
autocmd BufNewFile,BufRead app/**/*.erb set fenc=utf-8
autocmd BufNewFile,BufRead app/**/*.haml set fenc=utf-8
autocmd BufNewFile,BufRead app/**/*.rb set fenc=utf-8

autocmd BufNewFile,BufRead *.thor set filetype=ruby
autocmd BufNewFile,BufRead Thorfile set filetype=ruby

" rails.vim
let g:rails_level=4
let g:rails_statusline=1
" ruby omin complete
let g:rubycomplete_rails = 1


"================================================================================
" encoding
"================================================================================

" svn/git での文字エンコーディング設定
autocmd FileType svn :set fileencoding=utf-8
autocmd FileType git :set fileencoding=utf-8

"================================================================================
" backup, history
"================================================================================
set nobackup    " Don't keep a backup file
" set viminfo='50,<1000,s100,\"50 " read/write a .viminfo file, don't store more than
set viminfo='500,<10000,s1000,\"500 " read/write a .viminfo file, don't store more than
"set viminfo='50,<1000,s100,:0,n~/.vim/viminfo
set history=1000 " keep 50 lines of command line history

"================================================================================
" git, vcs
"================================================================================
" Bundle 'fugitive.vim'
nnoremap <unique> gG :exec ':silent Ggrep ' . expand('<cword>')<CR>

"================================================================================
" quickfix
"================================================================================
" QuickFix のサイズ調整,自動で抜ける 
function! s:autoCloseQuickFix()
  let qllen = min([10, len(getqflist())])
  cclose
  if qllen
    execute 'cw' . qllen
    normal <C-W><C-W>
  endif
  redraw
endfunction

autocmd QuickFixCmdPost * :call s:autoCloseQuickFix()

" quickfix を閉じる
nnoremap <unique> ec :cclose<CR>

"================================================================================
" other plugins
"================================================================================
" unite.vim
" 入力モードで開始する
let g:unite_enable_start_insert=1
nnoremap <silent> UU :<C-u>UniteWithCurrentDir buffer_tab file_mru file<CR>
nnoremap <silent> B :<C-u>Unite buffer file_mru file<CR>
nnoremap <silent> Uf :<C-u>UniteWithCurrentDir file buffer<CR>

" ESCキーを2回押すと終了する
au FileType unite nnoremap <silent> <buffer> <ESC><ESC> q
au FileType unite inoremap <silent> <buffer> <ESC><ESC> <ESC>q

" VimFiler
let g:vimfiler_edit_command = 'tabedit'

"================================================================================
" local setting
"================================================================================
" load ~/.vimrc.local
if filereadable(expand('$HOME/.vimrc.local'))
  source ~/.vimrc.local
endif

a.txt

# vim:set filetype=ruby:
def hoge
  puts "hello"
end