Problem with drawmatches()

Hi there, I making logo detection program that uses the SIFT method to detect a logo on image. The source code is [here](https://drive.google.com/open?id=0B7CADV0PAD_rcVpqR0p4amxwd0k). The folder with source images and logos("references" folder) is [here](https://drive.google.com/open?id=0B7CADV0PAD_rcjdBVjhxNXAtSjA). When I scrolling results of drawmatches(), program falling on image "13380-sony.jpg". What could be the problem? And how a source code could be optimized? P.S. Sorry my English.
P.P.S. I am beginner in OpenCV.