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).

Riproduci il comportamento nella GUI di MacVim con mvim -u NONE -U NONE -N, eseguendo il source di autoload/delimitMate.vim e plugin/delimitMate.vim prima di abilitare delimitMate. Confronta l’input della GUI con MacVim da riga di comando per i casi elencati di caratteri combinanti e spazi; il lavoro è completato quando entrambi producono il carattere e il comportamento del cursore previsti.