Nhibernate QueryOver don't get latest database changes

I am trying get a record updated from database with QueryOver. My code initially creates an entity and saves in database, then the same record is updated on database externally( from other program, manually or the same program running in other machine), and when I call queryOver filtering by the field changed, the query gets the record but without latest changes.

This is my code:

//create the entity and save in database
MyEntity myEntity = CreateDummyEntity();
myEntity.Name = "new_name";

MyService.SaveEntity(myEntity);

// now the entity is updated externally changing the name property with the 
// "modified_name" value (for example manually in TOAD, SQL Server,etc..)

//get the entity with QueryOver
var result = NhibernateHelper.Session
                 .QueryOver<MyEntity>()
                 .Where(param => param.Name == "modified_name")
                 .List<T>();

The previous statement gets a collection with only one record(good), BUT with the name property established with the old value instead of "modified_name".

How I can fix this behaviour? First Level cache is disturbing me? The same problem occurs with

CreateCriteria<T>();

The session in my NhibernateHelper is not being closed in any moment due application framework requirements, only are created transactions for each commit associated to a session.Save(). If I open a new session to execute the query evidently I get the latest changes from database, but this approach is not allowed by design requirement.

Also I have checked in the NHibernate SQL output that a select with a WHERE clause is being executed (therefore Nhibernate hits the database) but don´t updates the returned object!!!!

UPDATE

Here's the code in SaveEntity after to call session.Save: A call to Commit method is done

public virtual void Commit() 
{ 
  try 
  { 
    this.session.Flush(); 
    this.transaction.Commit();
  } 
  catch 
  { 
    this.transaction.Rollback(); 
    throw; 
  } 
  finally 
  { 
    this.transaction = this.session.BeginTransaction();
  } 
}

The SQL generated by NHibernate for SaveEntity:

NHibernate: INSERT INTO MYCOMPANY.MYENTITY (NAME) VALUES (:p0);:p0 = 'new_name'. 

The SQL generated by NHibernate for QueryOver:

NHibernate: SELECT this_.NAME as NAME26_0_ 
            FROM MYCOMPANY.MYENTITY this_ 
            WHERE this_.NAME = :p0;:p0 = 'modified_name' [Type: String (0)]. 

Queries has been modified due to company confidential policies.

Help very appreciated.

After search and search and think and think.... I´ve found the solution.

The fix: It consist in open a new session, call QueryOver<T>() in this session and the data is succesfully refreshed. If you get child collections not initialized you can call HibernateUtil.Initialize(entity) or sets lazy="false" in your mappings. Take special care about lazy="false" in large collections, because you can get a poor performance. To fix this problem(performance problem loading large collections), set lazy="true" in your collection mappings and call the mentioned method HibernateUtil.Initialize(entity) of the affected collection to get child records from database; for example, you can get all records from a table, and if you need access to all child records of a specific entity, call HibernateUtil.Initialize(collection) only for the interested objects.

Note: as @martin ernst says, the update problem can be a bug in hibernate and my solution is only a temporal fix, and must be solved in hibernate.