Hallo Andrea,
just an idea…
I havn’t a solution for you but what I would try to be sure if all linker settings are really right is to pick up aother small example dll project which complies/link fine without SDL.
Afterward add to this small dll example a few lines of SDL code and add the SDL lib to the project configuration and see if its still linking or not.
With this approuch you can verify if SDL is really your problem.
Chers
Pat