I trace the code , find it is shoutit.inc.php that handles the split :

Code
foreach ($words as $i =>$w) {
        if (strlen($words[$i]) > 20) {
                $words[$i] = wordwrap($words[$i], 20, "<br />", 1);
        }
}

I try to comment out these codes , it worked . My users can speak as they wish .
But I still hope future version can solve this problem.


English is not my native language. I try my best to express my thought precisely. I hope you understand what I mean. If any misunderstanding results from culture gaps, I apologize first.