string modified in onBeforeMessage not modified when received by onAfterMessage...

I am wondering if anyone who has more experience with the plugin
architecture could shed some light on possible reasons why I'm seeing the
behavior I'm seeing...

I have successfully implemented the IExodusChatPlugIn onBeforeMessage and
onAfterMessage methods.

Inside my onBeforeMessage implementation, I have modified the Body parameter
to be the empty string. (I've tried making over modifications, too. All with
the same effect.)

However, when I look at the contents of the Body parameter in the subsequent
onAfterMessage, the Body parameter contains the original (unmodified) Body
that was originally passed in to onBeforeMessage.

I have checked for the obvious mistakes related to references/pointers and
it looks like I've done the right thing.

Can anyone provide any other reasons why a Body modified in onBeforeMessage
wouldn't get handled such that the modified version is not passed in to the
onAfterMessage processing?

Thanks for any advice, ideas, etc.

- John -

P.S. I know that I can't change the string in onAfterMessage. I just
implemented a trace/breakpoint there to see whether the modifications in
onBeforeMessage are begin seen or not.