org.jawin.COMException: 80020006: Unknown name.

Hello all,

I've been developing with Jawin for the past couple of weeks having only
modest success.  Finally I've successfully managed to communicate with my
COM object and now I'm having more problems.  Here's a description:

I have a COM object with about 10 functions, taking a variety of
parameters.  I was curious to see how my little Java-COM bridge would hold
up under a bit of stress so I am iteratively calling almost all of the
functions on the object, like so:

>>OrderRunner.java (single main thread)

comclient = new _ComClient(ComClient.CLSID)
for (int i=0; i<50; i++)

comclient.startTransaction(...)
comclient.addItem(...)        //Various in & out & opt params
comclient.addCondiment(...)
comclient.addTax(...)
comclient.addTender(...)      //Various in & out & opt params
}
comclient.close(...)

<<

When I run this, I get the following exception:

org.jawin.COMException: 80020006: Unknown name.

 at org.jawin.marshal.GenericStub.dispatchInvoke0(Native Method)
 at org.jawin.marshal.GenericStub.dispatchInvoke
(GenericStub.java:201)
 at org.jawin.DispatchPtr.invokeN(DispatchPtr.java:587)
 at org.jawin.DispatchPtr.invokeN(DispatchPtr.java:555)
at ..._ComClient.AddItem(MatraCOMWrapper.java:211)
 ...OrderRunner.run2(MatraOrderRunner.java:67)
...TestClient.main(MatraAPITestClient.java:32)

I commented addItem and addTender, b