PHP runtime output after update

Required finfo but removed msi package, so removed php 5.3.0, downloaded 5.3.2 and installed. Now all of my sites have a maximum runtime error when they hit my custom error handlers. No problem until I update - has anyone encountered this before?

Checked all error logs and ran config files - nothing was allocated.

Edit:

Commented out the error handler and I get:

Warning: PDO :: __ construct () [pdo .-- construct]: [2002] Connection attempt failed because linked (did not try to connect via tcp: // localhost: 3306) in ... Core.php on line 60

Lines 59-60 from core.php:

$this->db = new PDO('mysql:dbname=' . $config['database']['db'],
        $config['login']['username'], $config['login']['password']);

      

        
        
        
      

    

PDO connects to MySQL 5. I'm starting to think it might be bug 5.3.2.