Version 1.11.1, error when archiving (no replies)

I have a high traffic server and since I've installed the new 1.11.1 version my server can't archive the stats.

I get always the same error:

SUMMARY OF ERRORS
Error: Got invalid response from API request: http://myserver.com/index.php?module=API&method=VisitsSummary.getVisits&idSite=1&period=day&date=last52&format=php&token_auth=b469c566445f9ec42b103668768bab39&trigger=archivephp. The response was empty. This usually means a server error. This solution to this error is generally to increase the value of 'memory_limit' in your php.ini file. Please check
Error: Got invalid response from API request: http://myserver.com/index.php?module=API&method=VisitsSummary.getVisits&idSite=2&period=day&date=last52&format=php&token_auth=b469c566445f9ec42b103668768bab39&trigger=archivephp. The response was empty. This usually means a server error. This solution to this error is generally to increase the value of 'memory_limit' in your php.ini file. Please check
Error: Got invalid response from API request: http://myserver.com/index.php?module=API&method=VisitsSummary.getVisits&idSite=3&period=day&date=last52&format=php&token_auth=b469c566445f9ec42b103668768bab39&trigger=archivephp. The response was empty. This usually means a server error. This solution to this error is generally to increase the value of 'memory_limit' in your php.ini file. Please check
Error: Got invalid response from API request: http://myserver.com/index.php?module=API&method=VisitsSummary.getVisits&idSite=4&period=day&date=last52&format=php&token_auth=b469c566445f9ec42b103668768bab39&trigger=archivephp. The response was empty. This usually means a server error. This solution to this error is generally to increase the value of 'memory_limit' in your php.ini file. Please check
Error: Got invalid response from API request: http://myserver.com/index.php?module=API&method=VisitsSummary.getVisits&idSite=5&period=day&date=last52&format=php&token_auth=b469c566445f9ec42b103668768bab39&trigger=archivephp. The response was empty. This usually means a server error. This solution to this error is generally to increase the value of 'memory_limit' in your php.ini file. Please check
Error: Got invalid response from API request: http://myserver.com/index.php?module=API&method=VisitsSummary.getVisits&idSite=6&period=day&date=last52&format=php&token_auth=b469c566445f9ec42b103668768bab39&trigger=archivephp. The response was empty. This usually means a server error. This solution to this error is generally to increase the value of 'memory_limit' in your php.ini file. Please check
6 total errors during this script execution, please investigate and try and fix these errors
ERROR: 6 total errors during this script execution, please investigate and try and fix these errors. First error was: Got invalid response from API request: http://myserver.com/index.php?module=API&method=VisitsSummary.getVisits&idSite=1&period=day&date=last52&format=php&token_auth=b469c566445f9ec42b103668768bab39&trigger=archivephp. The response was empty. This usually means a server error. This solution to this error is generally to increase the value of 'memory_limit' in your php.ini file. Please check
PHP Fatal error: 6 total errors during this script execution, please investigate and try and fix these errors. First error was: Got invalid response from API request: http://myserver.com/index.php?module=API&method=VisitsSummary.getVisits&idSite=1&period=day&date=last52&format=php&token_auth=b469c566445f9ec42b103668768bab39&trigger=archivephp. The response was empty. This usually means a server error. This solution to this error is generally to increase the value of 'memory_limit' in your php.ini file. Please check in /var/www/stats.softcatala.cat/misc/cron/archive.php on line 576

The configuration seems to be correct. Only I get a integrity problem message with the global.ini.php file. It seems that its size should be of 25072 and it's of 25073

I've increased the memory_limit value of my server to 4096M and I get the same message.

Can you help to solve my problem?