Why jackson rathbone break ashley greene? I heard they are dating sometimes

Ashley is dating Joe Jonas. Personally, I think that if anything was going to ACTUALLY happen between them that it would've already happened. I think that the whole Jackson/Ashley thing was just brought on by twihards who can't see the difference between movies and real life. Did you ever notice that the only time that Jackson and Ashley "Coo" over each other is in "Twilight" interviews. Just because Rob and Kristen actually got together in real life doesn't mind that they all will or should for that matter. Ok, there's my little rant...

so wikiasnwer is not very trustful website what jr web site is trustful or are they?

No, Wikiamswers is not a very trustful website. People post all kinds of made-up or things that they've "heard" all the time.