It might not be what you're looking for, but I think that "Blood is Thicker Than Water" is one where one of the boys is cursed into turning into a vampire while they're filming.

http://lady-krystal-79.livejournal.com/12764.html

I also know that there is at least one fic where Jared is a werewolf during filming, but it was pretty much all porn, so I don't know if that's what you're looking for or not.

Thank you! I really liked that fic and that actually was like what I was looking for.

I hope I can find more. I wouldn't mind reading that werewolf one, I'd just stop if it got too porno for my tastes.

Thanks again!

I'm glad that you liked that one.

I can't find the werewolf porn one right now. I know I keep stumbling across it, so I'll post a link when I find it.

So, you might not be looking for this anymore, but I did finally find the werewolf porn.

(I still feel strange even typing that, and I freaking have written werewolf porn...)

http://tryfanstone.co.uk/apsbarebonedandcrazyforyou.htm