I will try to adjust the value of innodb_buffer_pool_size at mysql configuration file (/etc/my.cnf). I think innodb_buffer_pool_size worth some highlights in
http://www.openideas.info/wiki/index.php?title=Pandora_3.0:Documentation_en:Anexo_AjusteMySQL. The default value is 8MB and the recommended is about 50-80% of all the RAM, depends if the server is a dedicated MySQL server or not... I was using the default value :-)
More info about innodb_buffer_pool_size can be found here:
http://dev.mysql.com/doc/refman/5.0/en/innodb-parameters.html#sysvar_innodb_buffer_pool_sizeRegards.