No receiver entered

[phillips, tim]

All,
 
I'm having problems using a workflow in 4.6b.
 
We're using workflow document type MMIINVOICE, which is based on task 7869
(Image:Assign).  The problem I'm having is with the event receivers; for
each workitem I execute, I get the error 'No Receiver entered' in SWEL.
 
I've checked the customising in SWE2, and there doesn't appear to be a
problem; the linkage is activated - additionally, my RFC user WF-BATCH is
configured.
 
I've just spent the last couple of hours buried in the debugger.  It would
appear to be failing in FM 'SWE_EVENT_GET_RECEIVERS', a part of master FM
'SWE_EVENT_CREATE'; it initially finds the correct receiver, but then fails
to find a matching entry for the workitem in table SWEINSTCOU - from what I
can see, it's something to do with the object key - specifically the absence
of MMIINVOICEFAX at the end.
 
As a result of this latter problem, the receiver found doesn't drop out at
the end.
 
Does this ring any bells with anyone? - I should imagine it's probably a
simple piece of config. I'm missing, but I can't put my finger on what it is
at present.
 
All help appreciated......
 
Regards,
 
Timbo