My problem was that enum parameter structure was messed after count() call.

Example:

$q->from('Company c')->where('c.company_type=?', 'BANK'); // ENUM parameter
$q->count();
$q->where('c.id=?','c3_'); // Integer parameter
$result = $q->execute(); // wrong result here

The solution is to replace in Doctrine_Query::getQuery()

        // reset the state
        if ( ! $this->isSubquery()) {
            $this->_aliasMap = array();
            $this->pendingAggregates = array();
            $this->aggregateMap = array();
        }

with

        // reset the state
        if ( ! $this->isSubquery()) {
            $this->_aliasMap = array();
            $this->pendingAggregates = array();
            $this->aggregateMap = array();
            $this->_enumParams = array(); // the solution
        }