When using a servant locator, the POA ignores any exception thrown on postinvoke
().  In fact, in the remote invokation case, the reply is actually sent to the 
client before postinvoke() is even called.

This seems to violate the POA spec which reads (in 11.3.6.2):

>The postinvoke operation is considered to be part of a request on an
>object.That is, the request is not complete until postinvoke finishes.
>If the method finishes normally but postinvoke raises a system exception,
>the method's normal return is overridden; the request completes with the
>exception.

I've actually tested this in 1.1.21.

I'll try to attach some test code.

It looks like postinvoke() is called via the destructor of the servant_upcall.
It would be possible to call postinvoke() earlier and tell the upcall object
not to call postinvoke() but code would have to be added to forward the
exception.