Mailchimp Subscription Form Block doesn't show

Mailchimp Subscription Form Block doesn't show when activited and generates this error:

Warning: MySQL server has gone away query: INSERT INTO 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:318:\"MySQL server has gone away\nquery: INSERT INTO accesslog (title, path, url, hostname, uid, sid, timer, timestamp) values('Blocks', 'admin/build/block', 'http://realcoachingradio.net/admin/build/block', '24.9.237.247', 1, 'd0mhuvvmveapjs4051i8sl4kh5', 12190, 1259514180)\";s:5:\"%file\";s:63:\"/home/realcoac/public_html/modules/statistics/statistics.module\";s:5:\"%line\";i:64;}', 3, '', 'http://realcoachingradio.net/admin/build/block', 'http://realcoachingradio.net/admin/build/block', '24.9.237.247', 1259514180) in /home/realcoac/public_html/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 (1, 'php', '%message in %file on line %line.', 'a:4:{s:6:\"%error\";s:12:\"user warning\";s:8:\"%message\";s:208:\"MySQL server has gone away\nquery: UPDATE sessions SET uid = 1, cache = 0, hostname = '24.9.237.247', session = '', timestamp = 1259514180 WHERE sid = 'd0mhuvvmveapjs4051i8sl4kh5'\";s:5:\"%file\";s:47:\"/home/realcoac/public_html/includes/session.inc\";s:5:\"%line\";i:68;}', 3, '', 'http://realcoachingradio.net/admin/build/block', 'http://realcoachingradio.net/admin/build/block', '24.9.237.247', 1259514180) in /home/realcoac/public_html/includes/database.mysql.inc on line 128