You should probably edit your post and remove the attachment since you're not allowed to post full vB files here.
To fix your newthread.php file you would need to chage this bit of code:
PHP Code:
$DB_site->query("INSERT INTO post (postid,threadid,title,username,userid,dateline,attachmentid,pagetext,allowsmilie,showsignature,ipaddress,iconid,visible,hidden) VALUES (NULL,'$threadid','".addslashes(htmlspecialchars($subject))."','".addslashes($postusername)."','$bbuserinfo[userid]','".time()."','$attachmentid','".addslashes($message)."','$allowsmilie','$signature','$ipaddress','$iconid','1','$hidden')");
To this:
PHP Code:
$DB_site->query("INSERT INTO post (postid,threadid,title,username,userid,dateline,attachmentid,pagetext,allowsmilie,showsignature,ipaddress,iconid,visible,hidden,isnews) VALUES (NULL,'$threadid','".addslashes(htmlspecialchars($subject))."','".addslashes($postusername)."','$bbuserinfo[userid]','".time()."','$attachmentid','".addslashes($message)."','$allowsmilie','$signature','$ipaddress','$iconid','1','$hidden','Y')");
Then you should upload the myvb_install.php file and select the option to update your news posts. That should update all the posts in that forum.