Message is missing MPI headers. Verify that all participants have it enabled.

Hi,

i'm trying to measure message processing performance using blazeds, i create more than 3 different flex
application, some using HTTPService, Other using a Java Factory and so on, but always got the same error:

Error: Message is missing MPI headers. Verify that all participants have it enabled.
at mx.messaging.messages::MessagePerformanceUtils()[C:\autobuild\3.2.0\f rameworks\projects\rpc\src\mx\messaging\messages\MessagePerformanceUti ls.as:106]
at traderdesktop/messageHandler()[C:\Projects\Flex\marketdata\src\trader desktop.mxml:144]
at flash.events::EventDispatcher/dispatchEventFunction()
at flash.events::EventDispatcher/dispatchEvent()
at mx.messaging::AbstractConsumer/http://www.adobe.com/2006/flex/mx/internal::messageHandler()[C:\autobu ild\3.2.0\frameworks\projects\rpc\src\mx\messaging\AbstractConsumer.as :727
at mx.messaging::ConsumerMessageDispatcher/messageHandler()[C:\autobuild \3.2.0\frameworks\projects\rpc\src\mx\messaging\ConsumerMessageDispatc her.as:246]
at flash.events::EventDispatcher/dispatchEventFunction()
at flash.events::EventDispatcher/dispatchEvent()
at mx.messaging::ChannelSet/messageHandler()[C:\autobuild\3.2.0\framewor ks\projects\rpc\src\mx\messaging\ChannelSet.as:1363]
at flash.events::EventDispatcher/dispatchEventFunction()
at flash.events::EventDispatcher/dispatchEvent()
at PollCommandMessageResponder/resultHandler()[C:\autobuild\3.2.0\framew orks\projects\rpc\src\mx\messaging\channels\PollingChannel.as:746]
at mx.messaging::MessageResponder/result()[C:\autobuild\3.2.0\frameworks \projects\rpc\src\mx\messaging\MessageResponder.as:199]

I really appreciate some help !