Originally Posted by Proverbs2
The rom is already rooted. Do you mean that you don't see the Superuser app in the app tray? That's normal, and it doesn't mean that Superuser isn't installed. You can access the superuser app in settings > Superuser. If you don't see it there, you can enable it by going to Developer options > Root access. (If you don't see Developer options under settings, you can enable that by tapping 7 times on the build number under "about phone.")
I found this in the meantime. I used to have the superuser app and when I saw it was not here I thought it was the origin of my problem (an app requiring root and doesn't getting it).
But then I found the menu option and allowed the app to get root.
About the developper options, I searched a little bit before finding that I had to tap 7 times on le build number to get the menu. So thank you again, for those who will know it through this thread (if there are some) !