some error after running well, session star

Dear friends,
I have a month working very well with SuiteCRM after a successful installation, but today I got these errors. Could you help me with a clue to solve it?

I have over me many angry sellers pushing me to solve it, after a big effort to convince them to use SuiteCRM. Thanks a lot for your help.

Warning: session_start() [function.session-start]: Cannot send session cache limiter - headers already sent (output started at /home3/carlosac/public_html/mexicoquerido.mx/mqcrm/metadata/accounts_opportunitiesMetaData.php:1) in /home3/carlosac/public_html/mexicoquerido.mx/mqcrm/include/MVC/SugarApplication.php on line 602

Warning: Cannot modify header information - headers already sent by (output started at /home3/carlosac/public_html/mexicoquerido.mx/mqcrm/metadata/accounts_opportunitiesMetaData.php:1) in /home3/carlosac/public_html/mexicoquerido.mx/mqcrm/include/utils.php on line 2698

Reading similar problem at the forum, some one recommends modify error reporting in php.ini, I checked it and it’s error_reporting = E_ALL & ~E_NOTICE & ~E_DEPRECATED & ~E_STRICT so the problem is not here.

An now new error has been added, I have 3 now:

Warning: session_start() [function.session-start]: Cannot send session cookie - headers already sent by (output started at /home3/carlosac/public_html/mexicoquerido.mx/mqcrm/metadata/accounts_opportunitiesMetaData.php:1) in /home3/carlosac/public_html/mexicoquerido.mx/mqcrm/include/MVC/SugarApplication.php on line 602

Warning: session_start() [function.session-start]: Cannot send session cache limiter - headers already sent (output started at /home3/carlosac/public_html/mexicoquerido.mx/mqcrm/metadata/accounts_opportunitiesMetaData.php:1) in /home3/carlosac/public_html/mexicoquerido.mx/mqcrm/include/MVC/SugarApplication.php on line 602

Warning: Cannot modify header information - headers already sent by (output started at /home3/carlosac/public_html/mexicoquerido.mx/mqcrm/metadata/accounts_opportunitiesMetaData.php:1) in /home3/carlosac/public_html/mexicoquerido.mx/mqcrm/include/utils.php on line 2698