Kenneth Bull to SDL I noticed in trunk/SDL/src/video/win32/SDL_win32events.c, in this code here... ... if the device handle isn't found in mice[], which it won't be if the mouse was plugged in after SDL_Init, then you end up with an uninitialized value in index, which is then passed to various SDL_SendMouse* functions.

/**
 * Part of SDL test suite.
 *
 * Written by Edgar Simo "bobbens"
 *
 * Released under Public Domain.
 */


#ifndef _TEST_AUDIO
#  define _TEST_AUDIO


int test_audio (void);


#endif /* _TEST_AUDIO */