title: Grails problem with nullable contraint in domain class
body: <p>I'm having the following problem with grails' 1.2.1 domain classes:</p>
  
  <p>When I set a constraint attr(nullable:true) and attr is <strong>int</strong> or <strong>bool</strong>, this condition isn't reflected in the db (postgresql 8.4). However, if attr is a <strong>String</strong>, the DB is consistent with the situation.</p>
  
  <p>Any hints ?</p>
  
  <p>Thanks</p>