[horde] ingo: can't add rules

[A. Schulze]

Jan Schneider:

> In ingo/lib/Factory/Storage.php, you can check if the created  
> instance is indeed an instance of Ingo_Storage_Prefs.

I added some logging into ingo/lib/Factory/Storage.php
line 46, $driver = $GLOBALS['conf']['storage']['driver'];
  -> $driver = 'prefs'

line 66, $class = 'Ingo_Storage_' . $driver;
  -> $class = 'Ingo_Storage_Prefs'

line 67, if (class_exists($class))
  -> is true

line 68, $params = Array
(
     [maxsize] => 10485760
     [driver] => KolabImap
)

but after line 68, $this->_instances[$driver] is still empty.
means to me: new $class($params) failed ?

That may be a reason?