Try downloading 5.3 and update your site. The upgrade instructions are in the doc folder.
If you want to try and patch your file the lines I am talking about for $desc are posted above.
The code block you posted is down the bottom of showphoto.php for the comments. The one you need to find is about the middle do a search for the $desc variable and you will find your lines. They should be as I post above in post 4