Undesired behavior with a few effects in Firefox 26.0

[curtisk]

Firefox 26.0 Windows
On your demo page the following effects exhibit extreme "jitters":
*Bubble Float Left/Right/Top/Bottom
*Outline Inward

How to reproduce: on any of the speech bubble ones just move the cursor to roughly where the :before arrow and the box slide apart, what will happen is that the animation will happen, and the cursor will change from the hand back to arrow, animation will start to slide back in and get re-triggered non stop making the animation stutter and the cursor flip between arrow/hand non stop until you move away. With Outline Inward, if the cursor is roughly where the outline first appears when the animation starts, same idea

I've tested with Firefox 26.0, Chrome 32.0.1700.76 m and IE11, and Firefox is the only one where it can get "caught" in the animation

Nice collection of effects overall!