title: Html.ValidationSummary showing duplicate error messages
body: <p>I have searched and Googled for the answer to this question to no avail. I'm using EF4 and ASP.NET MVC2 and I have an EF4 entity "Award" with a non-nullable string field, "RecipientID".  I'm using DataAnnotations for server-side validation, so in my "Award" partial class I've set up the RecipientID to have the Required attribute.  When I try to submit the form with the RecipientID text box empty, I see my error message "Please enter a recipient" in the Html.ValidationSummary twice.</p>
  
  <p>Would this be because the error is being thrown both by the entity (in that it is a non-nullable field with a null value), as well as the application?  Whatever the reason, is there a way to "fix" this and have the error message show up only once? (Fix being in quotations because I'm not sure if this is intended behavior or not.)  I didn't think it would be necessary to include relevant code, but I will if it's needed.</p>
  
  <p>Thank you in advance for your help.</p>