Warning: imagejpeg() [function.imagejpeg]: Unable to open '/home/SITENAME/public_html/files/cache/052f225905c1618003df0c5088aec7a9.jpg' for writing: Permission denied in /home/SITENAME/public_html/concrete/helpers/image.php on line 172

Vacié el directorio del caché y aún no tengo suerte, y si cambio los permisos en la carpeta del caché, obtengo otro error y no puedo usar el sitio en absoluto

Warning: require_once(Zend/Cache/Backend/File.php) [function.require-once]: failed to open stream: No such file or directory in /home/MYACCOUNT/public_html/concrete/libraries/3rdparty/Zend/Cache.php on line 133

Fatal error: require_once() [function.require]: Failed opening required 'Zend/Cache/Backend/File.php' (include_path='.:/usr/lib/php:/usr/local/lib/php:/home/owen/php') in /home/MYACCOUNT/public_html/concrete/libraries/3rdparty/Zend/Cache.php on line 133

No lo entiendo Nunca he tenido este problema antes.