hello manu, if you can, pls see if it's translated at the transifex. we haver hard time recently with checking out the language files over API from transifex... it's just extremaly slow (takes tens of minutes to checkout opc lang files)
i will add this into next opc version once translated.
Both frontend and backend fully translated in spanish, ill check carefully once is included in the package and correct anything I see in transifex but should be most correct.