If Youtube videos do not play reload the page, that's a Youtube bug.
Or maybe now, a few years later, it's a new bug ;-)

Danger Mouse & Daniele Luppi - Two Against One ft. Jack White

Battles - Ice Cream (Featuring Matias Aguayo)

Zoos of Berlin - Electrical Way

Tom Waits - God's Away On Business

Wormskull - Sound Of Hell