First youtube started not loading videos, then almost all google products had problem. I had 12.04 and 12.10 on Asus N56VM. There was that problem. Now I have 13.04 on same machine. It still is. I have chrome, chromium and firefox. There is no difference. İnternet is generally fine. The problem is only on google products.
Changing DNS not worked. I tried lots of DNS servers.
I tried with 3 different ISPs.
It is not a Flash Player issue I think, because the problem is on all of Google services (Gmail, Calendar, Maps), not only YouTube.
Tried disabling hardware acceleration option on Flash Player.
The problem is temporary. Some times Google.com, Gmail or Youtube work, some times not. Thus so difficult to track the problem.
These are some links related to my question. It is the same problem and no answer.
Edit 2: Question marked as duplicate. Okay, question is same (I noticed that when it marked, sorry). But the answer to that question is "change DNS" and I said it does not work for me.
Edit 3: I noticed that If I sing out from google account Youtube works well on all of my browsers(Chrome, Chromium, Firefox). I tried with different google accounts of mine on different browsers. Result is same. Finally I catch something to track this problem. If I'm signed in to google there is problem with google products.