Mysql 5.5 and PHP Mysql API Version 5.1.41

Hey there, I've just migrated to Mysql 5.5 from source and it works like a charm. Still every now and then (in intervals of approximatly an hour) I get the following error: Error: Uncaught exception 'PDOException' with message 'SQLSTATE[HY000] [2013] Lost connection to MySQL server at 'reading initial communication packet', system error: 110' in /home/ydadmin/build/lieferando.de/11720/library/Zend/Db/Adapter/Pdo/Abstract.php:129 Stack trace: #0 /home/ydadmin/build/lieferando.de/11720/library/Zend/Db/Adapter/Pdo/Abstract.php(129): PDO->__construct('mysql:port=6664...', '#####', '#####', Array) #1 /home/ydadmin/build/lieferando.de/11720/library/Zend/Db/Adapter/Pdo/Mysql.php(96): Zend_Db_Adapter_Pdo_Abstract->_connect() #2 /home/ydadmin/build/lieferando.de/11720/library/Zend/Db/Adapter/Abstract.php(448): Zend_Db_Adapter_Pdo_Mysql->_connect() #3 /home/ydadmin/build/lieferando.de/11720/library/Zend/Db/Adapter/Pdo/Abstract.php(238): Zend_Db_Adapter_Abstract->query('SET NAMES 'utf8...', Array) #4 /home/ydadmin/build/lieferando.de/11720/application/Bootstrap.php(99): Zend_Db_Adapter_Pdo_Abstract->query('SET NAMES 'utf8...') #5 /home/ydadmin/build/lieferando.de/11720/library/Zend/App in /home/ydadmin/build/lieferando.de/11720/library/Zend/Db/Adapter/Pdo/Abstract.php on line 144 It is like any queue is running full and this is the result, but actually no clue. My first guess is the API Version of the mysql client I am using with the precompiled php binaries (Ubuntu 10.10 Server, PHP 5.3.2-1ubuntu4.7 with Suhosin-Patch (cli) (built: Jan 12 2011 18:36:55)) Does anyone else have the same problems? Thanks for any help, Matthias