Debug errors in error log

My site script is currently giving me a couple of errors that are showing up in error log. I believe one of these two errors is causing my site to hang on page loads occasionally. Its basically two unrelated errors. The first is regarding "file does not exist...." it randomly says it cant find files that are actually there. Other times its looking for a file called "undefined". This happens many times a minute. The other error is: "PHP Fatal error: 1064 You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '0) AND server_status='Yes' LIMIT 0,1' at line 1 in /home/sitename/public_html/common/classes/[login to view URL] on line 61" This happens every couple of minutes. Im using Agriya Rayzz 2.3 for my adult video sharing site. Id like someone to have a look and resolve these errors. They may be in the PHP code or server setup.