Scrolling problem in Safari on a Mac

Scrolling problem in Safari on a Mac

I have a unusual problem. I have developed a website http://www.maimoon.net/clients/shusain using #jQuery animation. When you land on the link & pass through the homepage you'll see a gallery & a man seated on the bottom left side. When you click and drag the man the gallery strip above moves.

BUT! if you see the video http://youtu.be/E0y7kva2IXk you'll see that this animation reacts weirdly (The above gallery only moves when the man is pushed to the extreme right) in Safari on a Mac. Otherwise on all the other browsers & any other OS it works fine. I can't figure out what the problem is here & I can't work on it because I don't have a MAC.

Any help would be highly appreciated.

Regards
Murtaza Frosh