well i said this before but i can always repeat. I am using osx ,eclipse and i use it to write for arduino. The code is all the libraries that Arduino Ide has on the example for Ethernet Shield there is nothing that i wrote. After all the steps at the playground they give the projects ready. So there is nothing i did wrong on this except if the playground have them wrong.Every .cpp file has some problems and in each .cpp file the problems are the same so i gave you in the first post what error (in which function) every .cpp file gives. Please read it if you can help me. The compiler soes not give any error when i open eclipse and build all for first time. Error begun when i try to open at the editor any of these .cpp files.