Inside the file .\OpenRiaServices.DomainServices.Client\Framework\Silverlight\Data\Entity.cs there is a different way that validation is being handled.
Silverlight calls Validator.TryValidateProperty but (in my instance) WPF calls Validator.ValidateProperty.
Inside WPF the validation does not complete as an exception is being throw if the property representing the field is invalid.
Changing the code to call Validator.TryValidateProperty (to match the Silverlight platform) continues as I would have expected.
Comments: Try out 4.5.0-beta3 it should solve the isse
Silverlight calls Validator.TryValidateProperty but (in my instance) WPF calls Validator.ValidateProperty.
Inside WPF the validation does not complete as an exception is being throw if the property representing the field is invalid.
Changing the code to call Validator.TryValidateProperty (to match the Silverlight platform) continues as I would have expected.
Comments: Try out 4.5.0-beta3 it should solve the isse