Help: il sito crasha quando sono inseriti commenti da utenti non registrati!

Negli ultimi due giorni (e non ho fatto modifiche al sito) quando un utente non registrato prova ad inserire un commento sul mio sito compare il sito si impalla e compare una pagina che riporta tutti questi messaggi d'errore:

Warning: MySQL server has gone away query: INSERT INTO watchdog (uid, type, message, variables, severity, link, location, referer, hostname, timestamp) VALUES (0, 'php', '%message in %file on line %line.', 'a:4:{s:6:\"%error\";s:12:\"user warning\";s:8:\"%message\";s:257:\"MySQL server has gone away\nquery: SELECT s.lid, t.translation, s.version FROM locales_source s LEFT JOIN locales_target t ON s.lid = t.lid AND t.language = 'it' WHERE s.source = 'Service unavailable' AND s.textgroup = 'default'\";s:5:\"%file\";s:29:\"/modules/locale/locale.module\";s:5:\"%line\";i:375;}', 3, '', 'http://www.fondazionegiannipellicani.it/?q=comment/reply/1698', 'http://www.fondazionegiannipellicani.it/?q=node/1698', '93.37.155.142', 1270031171) in /includes/database.mysql.inc on line 128

Warning: MySQL server has gone away query: INSERT INTO watchdog (uid, type, message, variables, severity, link, location, referer, hostname, timestamp) VALUES (0, 'php', '%message in %file on line %line.', 'a:4:{s:6:\"%error\";s:12:\"user warning\";s:8:\"%message\";s:215:\"MySQL server has gone away\nquery: INSERT INTO locales_source (location, source, textgroup, version) VALUES ('/?q=comment/reply/1698', 'Service unavailable', 'default', '6.16')\";s:5:\"%file\";s:29:\"/modules/locale/locale.module\";s:5:\"%line\";i:391;}', 3, '', 'http://www.fondazionegiannipellicani.it/?q=comment/reply/1698', 'http://www.fondazionegiannipellicani.it/?q=node/1698', '93.37.155.142', 1270031171) in /includes/database.mysql.inc on line 128

Warning: MySQL server has gone away query: INSERT INTO watchdog (uid, type, message, variables, severity, link, location, referer, hostname, timestamp) VALUES (0, 'php', '%message in %file on line %line.', 'a:4:{s:6:\"%error\";s:12:\"user warning\";s:8:\"%message\";s:87:\"MySQL server has gone away\nquery: DELETE FROM cache WHERE cid LIKE 'locale:%'\";s:5:\"%file\";s:19:\"/includes/cache.inc\";s:5:\"%line\";i:175;}', 3, '', 'http://www.fondazionegiannipellicani.it/?q=comment/reply/1698', 'http://www.fondazionegiannipellicani.it/?q=node/1698', '93.37.155.142', 1270031171) in /includes/database.mysql.inc on line 128
Service unavailable
Warning: MySQL server has gone away query: INSERT INTO watchdog (uid, type, message, variables, severity, link, location, referer, hostname, timestamp) VALUES (0, 'php', '%message in %file on line %line.', 'a:4:{s:6:\"%error\";s:12:\"user warning\";s:8:\"%message\";s:289:\"MySQL server has gone away\nquery: SELECT s.lid, t.translation, s.version FROM locales_source s LEFT JOIN locales_target t ON s.lid = t.lid AND t.language = 'it' WHERE s.source = 'Spambot detected (action: 503 Service unavailable).' AND s.textgroup = 'default'\";s:5:\"%file\";s:29:\"/modules/locale/locale.module\";s:5:\"%line\";i:375;}', 3, '', 'http://www.fondazionegiannipellicani.it/?q=comment/reply/1698', 'http://www.fondazionegiannipellicani.it/?q=node/1698', '93.37.155.142', 1270031171) in /includes/database.mysql.inc on line 128

Warning: MySQL server has gone away query: INSERT INTO watchdog (uid, type, message, variables, severity, link, location, referer, hostname, timestamp) VALUES (0, 'php', '%message in %file on line %line.', 'a:4:{s:6:\"%error\";s:12:\"user warning\";s:8:\"%message\";s:247:\"MySQL server has gone away\nquery: INSERT INTO locales_source (location, source, textgroup, version) VALUES ('/?q=comment/reply/1698', 'Spambot detected (action: 503 Service unavailable).', 'default', '6.16')\";s:5:\"%file\";s:29:\"/modules/locale/locale.module\";s:5:\"%line\";i:391;}', 3, '', 'http://www.fondazionegiannipellicani.it/?q=comment/reply/1698', 'http://www.fondazionegiannipellicani.it/?q=node/1698', '93.37.155.142', 1270031171) in /includes/database.mysql.inc on line 128

Warning: MySQL server has gone away query: INSERT INTO watchdog (uid, type, message, variables, severity, link, location, referer, hostname, timestamp) VALUES (0, 'php', '%message in %file on line %line.', 'a:4:{s:6:\"%error\";s:12:\"user warning\";s:8:\"%message\";s:87:\"MySQL server has gone away\nquery: DELETE FROM cache WHERE cid LIKE 'locale:%'\";s:5:\"%file\";s:19:\"/includes/cache.inc\";s:5:\"%line\";i:175;}', 3, '', 'http://www.fondazionegiannipellicani.it/?q=comment/reply/1698', 'http://www.fondazionegiannipellicani.it/?q=node/1698', '93.37.155.142', 1270031171) in /includes/database.mysql.inc on line 128

Warning: MySQL server has gone away query: INSERT INTO watchdog (uid, type, message, variables, severity, link, location, referer, hostname, timestamp) VALUES (0, 'php', '%message in %file on line %line.', 'a:4:{s:6:\"%error\";s:12:\"user warning\";s:8:\"%message\";s:1277:\"MySQL server has gone away\nquery: INSERT INTO watchdog\n (uid, type, message, variables, severity, link, location, referer, hostname, timestamp)\n VALUES\n (0, 'antispam', '%message<p>Additional information:</p>%items', 'a:2:{s:8:\\"%message\\";s:51:\\"Spambot detected (action: 503 Service unavailable).\\";s:6:\\"%items\\";s:460:\\"<div class=\\"item-list\\"><ul><li class=\\"first\\"><strong>SQL</strong>: SELECT 1 FROM comments c in /includes/database.mysql.inc on line 128

Warning: MySQL server has gone away query: INSERT INTO watchdog (uid, type, message, variables, severity, link, location, referer, hostname, timestamp) VALUES (0, 'php', '%message in %file on line %line.', 'a:4:{s:6:\"%error\";s:12:\"user warning\";s:8:\"%message\";s:338:\"MySQL server has gone away\nquery: INSERT INTO accesslog (title, path, url, hostname, uid, sid, timer, timestamp) values('Anteprima commento', 'comment/reply/1698', 'http://www.fondazionegiannipellicani.it/?q=node/1698', '93.37.155.142', 0, 'sq4qo85dd0kqdme8k65kasosc0', 62069, 1270031171)\";s:5:\"%file\";s:37:\"/modules/statistics/statistics.module\";s:5:\"%line\";i:64;}', 3, '', 'http://www.fondazionegiannipellicani.it/?q=comment/reply/1698', 'http://www.fondazionegiannipellicani.it/?q=node/1698', '93.37.155.142 in /includes/database.mysql.inc on line 128

Warning: MySQL server has gone away query: INSERT INTO watchdog (uid, type, message, variables, severity, link, location, referer, hostname, timestamp) VALUES (0, 'php', '%message in %file on line %line.', 'a:4:{s:6:\"%error\";s:12:\"user warning\";s:8:\"%message\";s:4233:\"MySQL server has gone away\nquery: UPDATE sessions SET uid = 0, cache = 0, hostname = '93.37.155.142', session = 'messages|a:1:{s:5:\\"error\\";a:8:{i:0;s:317:\\"user warning: MySQL server has gone away\\nquery: SELECT s.lid, t.translation, s.version FROM locales_source s LEFT JOIN locales_target t ON s.lid = t.lid AND t.language = &#039;it&#039; WHERE s.source = &#039;Service unavailable&#039; AND s.textgroup = &#039;default&#039; in /modules/locale/locale.module on line 375.\\";i:1;s:275:\\"user warning: MySQL server has gone away\\nquery: INSERT INTO locale in /includes/database.mysql.inc on line 128