We had similar problem. here are postings on another forum. The unit in the first part of the first posting and the second posting are other units that had similar problem. Our problem and solution, with pictures showing before and after the work was done. It shows the steel added to the front and around the pin box.
First(ours starts on page 7 pictures of our unit start on page 8): http://www.cedarcreekrvclub.com/showthread.php?1096-Molding-Caulking-Issue
Second: http://www.cedarcreekrvclub.com/showthread.php?1735-Cracked-Welds-in-Frame-at-Pin-Box
Hope the helps and God bless,
Mike