Problem with delimitMate, gui and combining characters

I'm having this issue with delimitMate, but it doesn't happen with vim or gvim on linux, and it doesn't happen with MacVim on the command line, I can only reproduce it on the MacVim gui, so I'm starting to think the problem isn't the plugin.

Here are the exact steps to reproduce:

1. mvim -u NONE -U NONE -N

2. :so ~/.vim/bundle/delimitMate/autoload/delimitMate.vim<cr>

3. :so ~/.vim/bundle/delimitMate/plugin/delimitMate.vim<cr>

   (the files have to be there, obviously)

4. :DelimitMateOn<cr>

5. i<m-`>a (that's option + `, without macmeta)

   This should type à, but instead it types `à``. It only happens in the MacVim gui, at the command line it works as it should.

6. ```

   This should result in | (| is the cursor), but instead it does just ```. Again, it only happens in the gui.

The steps above use the regular US keyboard profile. I'm actually using the US International keyboard profile, which has many more combining characters, and this happens with others too (so this problem has nothing to do with the meta key, which isn't used with the other profile).

mvim -u NONE -U NONE -N を使って MacVim GUI での動作を再現し、delimitMate を有効にする前に autoload/delimitMate.vim と plugin/delimitMate.vim を source します。列挙された結合文字およびスペースのケースについて、GUI 入力とコマンドライン MacVim を比較します。両方で期待される文字とカーソルの動作が得られれば完了です。