How do i use WCF RIA by SOAP-OData-Json via Silverlight 4 - WP7 Client?

Hi guys,
 
I had a domain services (build in Silverlight Business Application Web) the Silverlight App local (e.g TestAppSilverlight and TestAppSilverlight.Web) is ok which I can implement CRUD method. (but I can't async this app !!!)
 
But when I deploy this domain services via SOAP-ODATA-JSON for another Silverlight App ,i got big problem when implement this service (with SOAP-VS 2010 debug some error inside the sevice,with ODATA-JSON are ok) and when I retrieve some record (via ODTA-JSON) i got message from IE like that :

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Webpage error details
User Agent: Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.1; WOW64; Trident/4.0; Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1) ; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; Media Center PC 6.0; .NET4.0C; .NET4.0E) Timestamp: Wed, 20 Apr 2011 03:27:25 UTC
Message: Unhandled Error in Silverlight Application Silverlight does not enable you to directly enumerate over a data service query. This is because enumeration automatically sends a synchronous request to the data service. Because Silverlight only supports asynchronous operations, you must instead call the BeginExecute and EndExecute methods to obtain a query result that supports enumeration. at System.Data.Services.Client.DataServiceQuery1.System.Collections.Generic.IEnumerable<TElement>.GetEnumerator() at System.Collections.Generic.List1..ctor(IEnumerable1 collection) at System.Linq.Enumerable.ToList[TSource](IEnumerable1 source) at SilverlightClient.MainPage..ctor() at SilverlightClient.App.Application_Startup(Object sender, StartupEventArgs e) at MS.Internal.CoreInvokeHandler.InvokeEventHandler(Int32 typeIndex, Delegate handlerDelegate, Object sender, Object args) at MS.Internal.JoltHelper.FireEvent(IntPtr unmanagedObj, IntPtr unmanagedObjArgs, Int32 argsTypeIndex, Int32 actualArgsTypeIndex, String eventName) Line: 1 Char: 1 Code: 0
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What should I do now ?
Please help me.