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 ;-)

DJ Kbz feat. DJ Axelito - Mega Francesita (DJ Gismo One RMX)

Dimitri Vegas & Like Mike - Tremor Ping Pong (DAWGS Edit) vs La La La vs I Like To Move It (DV&LM)