I browsed your website by using Firefox, Safari and Chrome. And i don't see any problem, 3d slideshow works as expecting.
Don't choose "Random" as transition effect, because some of the effects don't work in all browsers. Instead, use a specific transition that works with all browsers, (3d horizontal or 3d vertical are one of the effect that works in all browsers)
If you are not happy with that module, you can always find an alternative slideshow module, there are tones of free slideshow module available for Joomla. Check here: extensions.joomla.org/extensions/photos-a-images/slideshow