Youtube doesn't load

Hi everyone!

I have a macbook pro retina and the web site youtube doesn't load. In fact, it tries to load and after a certain time it stops and stay still to the same page. There's no error code, nothing. This is not a browser problem because it's the same with Firefox, chrome and Safari.
I updated Adobe Flash and java and it still do the same.

What strange is that when I switch to the Window part of the computer, it works just fine. So it really is a Mac problem.

What else could I do?

Dailymotion seems to work and vimeo too.

Thanks a lot :-D

Yesterday I tried to desinstall Adobe flash player 13 and install the 12. It worked but I coudn't see the comments section nor the thumbnails of each video (with the 13, youtube didn't load at all).

Now I'm still with 12 and by enable HTML5 with safari it works
But now I have the same exact problem than yesterday on firefox and chrome. The web site doesn't load.
And since I'm always using firefox I would really like it if it could work on it.

I'll tried to reinstall Adobe Flash 13 now.

Edit : No, with the reinstallation I still have the exact same problem. And now even Safari doesn't work.
2nd Edit : I've reinstall the 12, and now even with html5, nothing would work.

Now even on Windows with firefox youtube doesn't load entirely. It misses de comments and the thumbnails.
And now I have problems with googles images (who load only the fourth first row of images).

Youtube only works (perfectly) on IE on Windows.
I don't understand a thing.

Edit : Ah no, Firefox on Window doesn't load at all today.