Fixing retval = HeapFree(_crtheap, 0, pBlock); Error after class d-tor

[Despairy]

i have made a (not soooo good ) game using vs2008
i have a controller class which holds a level loader class

once i quit the game i do

delete Controller // from the main file

which goes to the controller destructor :

Controller::~Controller(){
	delete screen;
	delete loader;
	delete eventer;
}

which than go to the level loader

LevelLoader::~LevelLoader()
{
	eraseLevel();// function that deallocs all malloced info
}

everything is fine during the deletion and the ~levelLoader is finished
getting back to the ~controller

Controller::~Controller(){
	delete screen;
	delete loader;
	delete eventer;
} // AT THIS POINT EVERYTHING CRASHES

when the d-tor of the controller is finnished i get this error (img attached)
tryed changing the deletes to delete [] (not sure i understand the difference)
but that didnt work
i have a boolean that checks if i free the stuff more than once and i dont.

btw level loader and controlelr destructors are virtual if that makes any difference
been googling the problem but without success.

thank you appreciate your help!