Nivo Slider not working in Firefox

[Hayley]

I have a nivo slider on my website located at http://www.applecityrollerderby.com/ It works fine in Chrome and IE
It was working fine in Firefox, but it seems that the latest update may have broken it. Now the transitions are making the images appear sliced even after the transition. I can fix this by using only the fade transition but I'd like to find a way to keep the random transitions.
Additionally, the captions are now located above the images and the slider is forcing my content to the bottom of the page.

Any help would be appreciated. Thanks.