Hey Bao,
I’ve been troubleshooting the issue for some time now and still cannot determine the root of the problem; most probably it is a jQuery issue, or it may be connected more specifically with the way Firefox 24 handles the code of the Isotope plugin. In any case, I will keep looking into the problem, yet since the infinite scroll was already a customization to the theme which is not covered by the theme support guarantee, this bug will not be on top of my support priority list, so may take some time; in the meanwhile it could be worth turning to developers for additional man-hour assistance, e.g. on Fiverr or Tweaky.
Sincerely,
Andrew / Satori Studio