When I run my subselect which returns true, false or null and I want to access to this property(and the value is null) I've this error Unknown record property / related component "prikazce" on "Autoprovoz". I propose to change in Doctrine_Record::get()

if (isset($this->_values[$fieldName])) {
    return $this->_values[$fieldName];
}

to

if (array_key_exists($fieldName, $this->_values))
{
    return $this->_values[$fieldName];
}