My apache error log have lots of lines like: (ip xx-ed by me)
[Sun Sep 28 10:13:12 2003] [error] [client xxx.xxx.xxx.xxx] File does not exist: /var/www/html/lib/rte/@{hdr_tables}
I have similar experience. Obviously, it concerns the Rich Text Editor but don't know how. 
I have the same errors in my log file. Has anyone found out what causes them?