aggregator feeds can't be updated

I set up everything in enabling aggregator, I guess correctly but when I want to update my feeds, I get the error that the links seems to be broken. On Drupal 6.14, I can't even run Cron. I get a message like this:
Warning: MySQL server has gone away query: INSERT INTO drup_watchdog (uid, type, message, variables, severity, link, location, referer, hostname, timestamp) VALUES (1, 'php', '%message in %file on line %line.', 'a:4:{s:6:\"%error\";s:12:\"user warning\";s:8:\"%message\";s:717:\"MySQL server has gone away\nquery: INSERT INTO drup_watchdog\n (uid, type, message, variables, severity, link, location, referer, hostname, timestamp)\n VALUES\n (1, 'aggregator', 'The feed from %site seems to be broken, due to an error \\"%error\\" on line %line.', 'a:3:{s:5:\\"%site\\";s:32:\\"Chad and Sudan agree to end feud\\";s:6:\\"%error\\";s:31:\\"not well-formed (invalid token)\\";s:5:\\"%line\\";i:17;}', 4, '', 'http://givepacc.com/?q=admin/reports/status/run-cron&a in /home/givepacc/public_html/includes/database.mysql.inc on line 128
Any help will be appreciated.