Flex Carousel's transition suddely stopped working in Firefox (just white)

Awesome plugin. It’s been working perfectly up to this point, then today I notice my slider, instead of doing the scroll-to the left effect as the Flex Carousel slider does, it just flashes out to white then shows the next picture. It only seems to be happening on my Firefox v29.0, not IE or Chrome.
I uninstalled and installed the newest plugin, Meta Slider v2.9.
In the Save & Preview window, the effect works just fine.
The other sliders have no issues like this.

Thanks.

https://wordpress.org/plugins/ml-slider/