Resolution... After spending way too much time troubleshooting this problem, I broke down and ordered the enterprise edition. Uninstalled v6.0 professional, installed v6.0 enterprise and wouldn't you know it, problems disappeared.

What triggered the problems to suddenly begin - I still have no idea. There's something hokey going on with professional and RDO, as I've seen others reporting similar issues in this forum.

Good luck to those of you who also get tripped up by professional!!

Thanks