If you can PM me an admin account and your ftp details I can see if I can help you with this.
Trying to resolve this for you through posts is getting us nowhere.
well.. i think the problem is in MyShoutbox plugin..
last time, after placing:
<script type="text/javascript">
jQuery.noConflict();
</script>
in footer and header, forum is working properly..
and then i uninstall the MyShoutbox,. and transfer to ChangUonDyU - Extra File Chatbox ..
since i found bugs on Chatbox File.. i uninstall it and upload the MyShoutBox plugin again..
and now, i have the same issue again..
alright.. i figured out the problem..
i noticed the xmlhttp.php and the content inside was disappeared.. i dont know why..
i just replace the xmlhttp.php file from the latest version of MyBB and now my forum is up and working properly..
can you tell me how to avoid this issue in xmlhttp.php ?