nope now all of my tables collation utf8_general_ci
Are you 100% sure of that? Have you inspected the collation on specific table columns? Column collation could be different than table collation.
The only thing I know is when I installed MySql I set utf8 and collation at install time and it is the default for the installation. Maybe making it the default just for a database is not enough if the installation has different settings as the default.
Hope it helps,