First thing first : I updated calibre and installed the kobo utilities.
After that, I copied all I had on my SD card in my calibre library.
I powered my glo off and got the SD card out. I powered my device again on and sign out. It restarted and decided to update (so now, I'm with the 2.8.1 firmware) and only after that could I sign in again. I turned it off, inserted my SD card and repowered it. I'll see how it turns (I have seen, that previously that I put my SD card back inside its slot, the shelves where already there, so...) Now, I'll see how it behaves and how I'm to sync my calibre library with my kobo's (hoping the books will be put automatically in their shelves or I think I'll die before making it by hand).
I'll keep you informed on how it goes
