passing by reference... my darkest enemy actual reason below: In your case (without reference) the compiler generates a temporary object (int) for the first argument of your MyApplication constructor. You pass this temporary int to QApplication’s constructor (with int reference), which saves the address of this reference. Once your MyApplication constructor is done the temporary int is destroyed but QApplication still has its address.

LIBRARY "openalbridge"
EXPORTS
	openal_init
	openal_close
	openal_ready
	openal_loadfile
	openal_playsound	
	openal_pausesound
	openal_stopsound
	openal_playsound_loop
	openal_stopsound_free
	openal_freesound
	openal_toggleloop
	openal_setvolume
	openal_setglobalvolume
	openal_togglemute
	openal_fade
	openal_fadein
	openal_fadeout