Flip Animation Not Working On Firefox

I followed this tutorial to incorporate a card flip on my website. I learned the important lesson of not letting your website go live without testing on all major browsers, becau

Solution 1:

Assuming that you're trying to make just a flip:
You tried to accomplish too many rotations at once compared to David Walsh's example.
I've commented out the latter transform: rotate rules and therefore it works in Firefox.

Edit Updated jsfiddle with cleanup See my jsfiddle: http://jsfiddle.net/Volker_E/n27qM/4/
I've also added some comments for better code in my jsfiddle, like getting rid of -moz-box-shadow (just for Fx < 4.0) or don't include value units on values that are '0' and so on.

Regarding your question on general advice: Firefox' own developer tools are a good start, but the best tool in my opinion is Firebug. For a comparison of the two see What unique features does Firebug have that are not built-in to Firefox?
Or put your code not only into your question, but also on jsfiddle, so others can start fiddling around immediately! ;)