I get the SDL_DUMMY_ENUM assertion in SDL_types.h
You need to turn on the "enums as ints" option for your compiler:
For the free Borland compiler, add this command line option: -b
For Watcom C/C++, add this command line option: -ei
For Apple's MPW environment, add this command line option: -enum int
For CodeWarrior, go to the C/C++ Language settings menu for your project and check the "Enums Always Int" box.