org.jawin.COMException: 80020006: Unknown name. Oops! Read this copy!

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, because when I comment out the setting
of out parameters (Variant/String types)in AddTender() (in my COM dll) ,
then I dont get the exception.  For the record, I am using
Variant.ByrefHolder instances to contain Variant/Str classes on the Java
side.  Anyway - I'm clueless as to why this setting of out these
parameters in my COM object causes Jawin to fail.

Thanks for your help and sorry for the duplicate email,
- Erran