Dvallet, this article is pretty old: 1st may 2006! 6 years ago, C::B was not really the same.
When I am creating a new sdl on windows, project, I do this:
_ creating a new project, but an empty one
_ creating a C::B global variable (so, not in code) with "include" and "lib" fields filled
_ creating an empty project
_ adding it $(#sdl.include) in header path
_ adding it $(#sdl.lib) in lib path
_ Adding it "SDL" and "SDLmain" in libraries
_ Creating a main.cpp (or .c, depending on language)
_ enjoying
It is a bit longer than using official projects, but, honestly, I had enough problems with them and boring errors like the one you are having.
Notes:
_ ref for compiler global varialbles:
http://wiki.codeblocks.org/index.php?title=Global_compiler_variables_ checking documents' dates of resources you will find on internet is often a good idea, especially when it comes to a software. And DVP.com is not an exception: it sure have nice content for us, but it is an old site which contain some outdated content (but many interesting things too)