Mouse flickery

SDL Development
1

In fullscreen and double buffer the mouse only show if it moves. I use that
pseudocode

while(notfin){
see_events;
draw_all;
SDL_ShowCursor(true);
SDL_Flip(screen);
}

and i probe next too but in windowmode but mouse blink:

while(notfin){
see_events;
SDL_ShowCursor(false);
draw_all;
SDL_ShowCursor(true);
SDL_Flip(screen);
}

I use windows 98