DeserializationFailed Error when Submitted the SOAP Request

Hi,

Can anyone solve this issue?
When Submitted the SOAP Request there is a Deserialization error "Deserialized object with reference id '?' not found in stream." I am not able to understand why I am getting this exception.When I did the same thing from another tool ,it is working fine .I am able to get the response.

The XML which is generated in SOAP UI contains "<tas:request ser:Id="?" ser:Ref="?">". what are these? What should I pass over here.?

The error details are below

<s:Envelope xmlns:s="http://schemas.xmlsoap.org/soap/envelope/"><s:Body><s:Fault><faultcode xmlns:a="http://schemas.microsoft.com/net/2005/12/windowscommunicationfoundation/dispatcher">aeserializationFailed</faultcode><faultstring xml:lang="en-GB">The formatter threw an exception while trying to deserialize the message: There was an error while trying to deserialize parameter .The InnerException message was 'Deserialized object with reference id '?' not found in stream.'.  Please see InnerException for more details.</faultstring><detail><ExceptionDetail xmlns="http://schemas.datacontract.org/2004/07/System.ServiceModel" xmlns:i="http://www.w3.org/2001/XMLSchema-instance"><HelpLink i:nil="true"/><InnerException><HelpLink i:nil="true"/><InnerException i:nil="true"/><Message>Deserialized object with reference id '?' not found in stream.</Message><StackTrace>at System.Runtime.Serialization.XmlObjectSerializerReadContext.GetExistingObject(String id, Type type, String name, String ns)
   at System.Runtime.Serialization.XmlObjectSerializerReadContext.TryHandleNullOrRef(XmlReaderDelegator reader, Type declaredType, String name, String ns, Object&amp; retObj)
   at System.Runtime.Serialization.XmlObjectSerializerReadContext.InternalDeserialize(XmlReaderDelegator reader, String name, String ns, Type declaredType, DataContract&amp; dataContract)
   at System.Runtime.Serialization.XmlObjectSerializerReadContext.InternalDeserialize(XmlReaderDelegator xmlReader, Type declaredType, DataContract dataContract, String name, String ns)
   at System.Runtime.Serialization.DataContractSerializer.InternalReadObject(XmlReaderDelegator xmlReader, Boolean verifyObjectName, DataContractResolver dataContractResolver)
   at System.Runtime.Serialization.XmlObjectSerializer.ReadObjectHandleExceptions(XmlReaderDelegator reader, Boolean verifyObjectName, DataContractResolver dataContractResolver)
   at System.Runtime.Serialization.DataContractSerializer.ReadObject(XmlDictionaryReader reader, Boolean verifyObjectName)
   at System.ServiceModel.Dispatcher.DataContractSerializerOperationFormatter.PartInfo.ReadObject(XmlDictionaryReader reader, XmlObjectSerializer serializer)
   at System.ServiceModel.Dispatcher.DataContractSerializerOperationFormatter.DeserializeParameterPart(XmlDictionaryReader reader, PartInfo part, Boolean isRequest)</StackTrace><Type>System.Runtime.Serialization.SerializationException</Type></InnerException><Message>The formatter threw an exception while trying to deserialize the message: There was an error while trying to deserialize parameter .The InnerException message was 'Deserialized object with reference id '?' not found in stream.'.  Please see InnerException for more details.</Message><StackTrace>at System.ServiceModel.Dispatcher.DataContractSerializerOperationFormatter.DeserializeParameterPart(XmlDictionaryReader reader, PartInfo part, Boolean isRequest)
   at System.ServiceModel.Dispatcher.DataContractSerializerOperationFormatter.DeserializeParameters(XmlDictionaryReader reader, PartInfo[] parts, Object[] parameters, Boolean isRequest)
   at System.ServiceModel.Dispatcher.DataContractSerializerOperationFormatter.DeserializeBody(XmlDictionaryReader reader, MessageVersion version, String action, MessageDescription messageDescription, Object[] parameters, Boolean isRequest)
   at System.ServiceModel.Dispatcher.OperationFormatter.DeserializeBodyContents(Message message, Object[] parameters, Boolean isRequest)
   at System.ServiceModel.Dispatcher.OperationFormatter.DeserializeRequest(Message message, Object[] parameters)
   at System.ServiceModel.Dispatcher.DispatchOperationRuntime.DeserializeInputs(MessageRpc&amp; rpc)
   at System.ServiceModel.Dispatcher.DispatchOperationRuntime.InvokeBegin(MessageRpc&amp; rpc)
   at System.ServiceModel.Dispatcher.ImmutableDispatchRuntime.ProcessMessage5(MessageRpc&amp; rpc)
   at System.ServiceModel.Dispatcher.ImmutableDispatchRuntime.ProcessMessage31(MessageRpc&amp; rpc)
   at System.ServiceModel.Dispatcher.MessageRpc.Process(Boolean isOperationContextSet)</StackTrace><Type>System.ServiceModel.Dispatcher.NetDispatcherFaultException</Type></ExceptionDetail></detail></s:Fault></s:Body></s:Envelope>