In IE, How to create test for multiple mapping in one direction

hi, I created an Operation Mapping in ESB, which includes 2 steps mapping.

mapping1:

<source> <item> .. </item></source>

-->

<middle> <item> .. </item></middle>

mapping2:

<middle> <item> .. </item></middle>

-->

<target> <item> .. </item></target>

I test this OM in ESB, it works good.

However when I go to IE and tried to build a test scenario for it, it failed.

I used the "configuration wizard" of IE to build my test scenario, created the Communication Componet, Send receiver, etc as normal Operation Mapping does.

It reported a runtime error:

IllegalInstanceException: Cannot create target element /midd. Values missing in queue context. Target XSD requires a valu~

Looks like this exception happend at the step1 mapping. When I change my OM to only one step, everything OK.

Any special thing needed in IE for the multiple mapping in one OM?