Finally I had time to get my hands on source code =) So far about problems.
On win32, on start up I got a runtime hardware exception - something about privileged instruction. It turned out SDL_GL_GetProcAddress is __cdecl - not __stdcall, and because of thoughtless cast rwglGetProcAddress calls are being messed up.
I don't know if following block have much sense:
rwglGetProcAddress = SDL_GL_GetProcAddress("rglGetProcAddress");
rwglGetProcAddress = SDL_GL_GetProcAddress;
Why not just use SDL_GL_GetProcAddress everywhere? Personally, I'd completely ditch out all rwgl*|rgl* functions in favor of SDL_GL_*|gl*.