have you tried updating your flash driver? Or try opening it in a different web browser? Sometimes you just need to shutdown and re-open your web browser..
edited to say that I can't open these either directly...as they are not linking directly to you tube!
Solution...when you click on the link, you will open a new window and the address has m. infront of youtube (because it has been sent from a mobile???) just delete the m. and press return and it will take you to the you tube video.