Entity Framework losing Sql DateTime precision

I am querying my EDM using Entity SQL and am losing millsecond precision on my DateTime values. For example 2011/7/20 12:55:15.333 PM gets changed to 2011/7/20 12:55:15.000 PM.

I have confirmed that in SQL the milliseconds are recorded precisely.

There is a Precision attribute I can apply in the .edmx XML file, but I do not know what sort of values it takes,

      <Property Name="Timestamp"
                Type="DateTime"
                Nullable="false"
                Precision="???" />

Does anyone know how to use this precision attribute ?

Thanks.