I also found that when I was using google chrome, I couldn't watch any of the youTube videos........It wouldn't continue buffering the video because the driver which in google chrome uses it's own version was not updated to work with the current level needed in youTube.

Figured that out because I could play DVD movies on the computer, just nothing from youTube when using google chrome.

I changed over to firefox & youTube worked well.....sometimes a bit slow because I have an antique computer.....but at least it works.

Just something else to look at as a possible reason for problems.