Trying to respond all of your questions:
This is the build log after enabling -Wall in Global compiler options.
Switching to target: default
Compiling: glScene.cpp
Compiling: main.cpp
In file included from main.cpp:4:
glInit.cpp: In member function `void glInit::changeSize(GLsizei, GLsizei)':
glInit.cpp:25: error: `GLfoat' undeclared (first use this function)
glInit.cpp:25: error: (Each undeclared identifier is reported only once for each function it appears in.)
glInit.cpp:25: error: expected `;' before "height"
main.cpp: In function `LRESULT WndProc(HWND__*, UINT, WPARAM, LPARAM)':
main.cpp:80: error: conversion from `glInit*' to non-scalar type `glInit' requested
Process terminated with status 1 (0 minutes, 1 seconds)
4 errors, 0 warnings
Checked, that "GLfloat" is defined in gl.h and it's not between #define/#endif. And the gl.h file is the one that came with C::B install.
P.S.: I can send all the proyect via e-mail if anyone wants it