Hello, I'm back just for useless news sorry for the ones who have still some issues. It eventually worked for no reason, with the PC I talked about, and recently I changed my computer for a brand new one, running W7 64 again. I had some issues with Cubase 7 (previously Cubase SX 3) but again for no reason it's eventually working fine since December. Sorry for having no clues to give, I can only tell you to pray very hard.