forwarding work items

[Brian Bennings]

In one of our 4.5b systems, we have found were a user forwards a work item to
one person, but it ends up being forwarded to someone completely different.
When you look at the workflow logs, it shows that the work item was forwarded to
the intended recipient, but for whatever reason, it ends up in someone else's
inbox.
 
This does not happen 100% of the time for any user, sometimes it works.  This
also has occurred for multiple users, not just a single one.
 
What could have caused this?
 
Thanks,
Brian Bennings