From the online manual:
mysql_connect(): Too many connections
The server has maxed out the number of MySQL connections it allows. You can try turning persistent connections off by adding this to your config.php:
$config['MasterServer']['usepconnect'] = 0;
But if you still have problems after that, you will need ask your host to raise the maximum number of connections they allow.
Here is more info on that error:
http://dev.mysql.com/doc/refman/5.0/...nnections.html