Does FAST stack?

I doubt it does, but I know that Sabre, Invs, and Ruse stack.

I've never actually used fast on a character twice in a battle (Unless he'd been SLOWed), and so I'm curious if the effects double.

Of course, I could test it on my own, but I'd rather just hear it.

Besides, it's kind of a neat question, I think, and so... Let the forumites have an answer!