title: Symfony 1.4, Doctrine 1.2 : After editing an object, other related objects are deleted ?
body: <p>in my app, a monitor has many benchmarks (1 to many)
  in the monitor editing interface, when i save the modifications every benchmark having monitor_id the one that i edited is DELETED !</p>
  
  <pre><code>Monitor:
    tableName: monitor
    actAs:
      Timestampable: ~
    columns:
      id : {type: integer(4), primary: true, autoincrement: true}
      label: {type: string(45)}
      url: {type: string(80)}
      frequency: {type: integer}
      timeout: {type: integer}
      method: {type: enum, values: [GET, POST, HEAD, PUT, DELETE]}
      parameters: {type: string(255)}
      active : { type: boolean, notnull: true, default: 1 }
    relations:
      GroupsByAlert:
        class: sfGuardGroup
        local: monitor_id
        foreign: sf_guard_group_id
        refClass: Alert
        foreignAlias: Groups
      Accidents:
        class: Accident
        local: id
        foreign: monitor_id
  
  Benchmark:
    #detect_relations: true
    tableName: benchmark
    actAs:
      Timestampable: ~
    columns:
      #id: {type: integer(4), primary: true,autoincrement: true}
      monitor_id: { type: integer(4)}
      server_id: { type: integer(4)}
      connexionTime: {type: string(45)}
      executionTime: {type: string(45)}
      responseTime: {type: string(45)}
      responseCode: {type: string(45)}
      responseMessage: {type: string(45)}
      responseBody: {type: blob}
    relations:
      Monitor:
        class: Monitor
        local: monitor_id
        foreign: id
      Server:
        class: Server
        local: server_id
        foreign: id
  </code></pre>
  
  <p>Any idea?</p>