receive as pick branch trigger does not fire

I have a WF4 Service with a flowchart as the root activity. It contains multiple correlated receive activites and decision branching to step through an approval process. The receive activities work perfectly until I try and use one as the trigger for a pick branch.

I am running tracking so can see that the receive is opened and in the persistance I can see the associated bookmark. When I send a client message with the receive type it does not trigger. I have a delay pick branch that fires OK but then the subsequent receive also does not work.

I have checked these receive activities individually and they work OK when not used as the pick trigger. I have tried the pi开发者_运维问答ck within a Sequence and a While but no difference.

I cannot see any difference between my implementation and may examples on the web. Am I missing something extra required when the receive is encapsulated by a pick branch?

There is nothing special about a PickBranch trigger that would cause a receive to behave differently so I suspect it is something with the Receive itself. What kind of errors are you seeing at the client application?