Any idea what could be done to avoid this ? I tried commenting the recommended parameters in the installation guide but I can't really see a difference (also those recommended in znuny installation guide) :
max_allowed_packet = 64M
query_cache_size = 32M
innodb_log_file_size = 256M
[client]
max_allowed_packet=256M
[mysqld]
innodb_file_per_table
innodb_log_file_size = 256M
max_allowed_packet=256M