Problems of applying the fundamental frequency estimator, YIN

I try to apply a fundamental frequency estimation program called YIN developed by Alain de Cheveigne in 2002, with the program freely available from http://www.auditory.org/postings/2002/26.html. Arguably, it is still among the best. However, this program was wrote > 10 years ago and many of the associated functions were wrote in C and only compatible with 32 bit Matlab version. I am working in 64 bit Windows system. Naturally, it does work for me. Considering that many people are using YIN, some of you should also using 64 bit Matlab version. I wonder how do you guys solve this problem. Any practical suggestion will be appreciated. Many thanks. Jinhong