What I think is going on is that when exploding an image, a face is created which - in your case - is merged with the face of the house and the (default) colour overrides the image just exploded. Best would be to post the model like Remus suggests. You can also try to follow these steps; right click on the image > Texture > Position and (without doing anything else there) hit Enter. Select the Paint bucket tool and hold the Alt key pressed > Sample the positioned image apply the image material on that face. You may still need to position it a bit (use the method like above to get into the positioning menu)