I've apparently exhausted the chance for resolution of this problem on the Microsoft Community site, and hope TechNet can come up with something.  Below is a link to what's already been asked, answered, and tried so far.

http://answers.microsoft.com/en-us/windowslive/forum/livemail-program/valid-email-addresses-dont-work-in-bcc-line-of/333c218f-d5ff-401e-ada1-3c6b74adbc6d

Bruce