title: Model Validation Regex never matches
body: <p>I have the following Regex annotation:</p>
  
  <pre><code>    [RegularExpression(@"(?=.{6,})(?=(.*\d){1,})(?=(.*\W){1,})", ErrorMessage = "Password is not strong enough!")]
      public string Password { get; set; }
  </code></pre>
  
  <p>This is a copy/paste from my Regex I use in my MembershipProvider, where it works, as I can register with passwords like "admin1*". I tested this regex in RegexHero as well and it does work.</p>
  
  <p>When I post back my form to the controller the value is also present, yet the model never validates.</p>
  
  <p>Anyone have a clue as to what this could be?</p>
  
  <p>Thanks in advance,</p>
  
  <p>Edit:</p>
  
  <p>I tested with a Regex that validates strings containing only 5 numbers, and that does validate when I input 12345, and fails with other string like "abc". So the regex mechanism seems to work.. </p>