Just to add to the whole Firefly thing, that also happend to Nathan Fillion. After Firefly, his other show Drive was dead after only 2 Episodes. I think something else was called out with him as well.

He amused the hell out of me in Serenity/Firefly, and any other movie/show he did.

Seems most of the cool people from that show can't seem to make it out side of the one show that made them Popular, Firefly.