When you talk about "the Arab Press" you have to be careful. Some of the most widely distributed and most influential newspapers in the Middle East are published in London. The fact of the matter is that the Israel-9/11 rumor, while common enough, rarely surfaces in the press. I'd be willing to be that when it has, it only appeared in wingnut columns ala Ann Coulter.
In any society where the official avenues of information are considered to be compromised, conspiracy theories take root. The fact of the matter is that, in information just like finance, the bad drives out the good. When people don't have confidence in the "legitimate" sources of information, they inevitably turn to the "underground" media, which are often factually inaccurate. Look at the internet. 90% of the stuff you find on the internet is bunk (compared to, say, only 50-60% in the American news media).
The same is true for Italy. Italians love conspiracy theories. And why not? Berlusconi owns 90% of the media. That figure hardly inspires one to put confidence in the Italian media. I think it may happen here, as well. Americans have always had a penchant for conspiracy theories, and they're fast losing confidence in their own media. We have gotten to the point where FOX is the #1 news channel and yet nobody takes it seriously. Who knows? Perhaps one day we'll start hearing theories about how the Michigan Militia orchestrated 9/11.