I've also noticed that the new "recent contacts" dialog shows the group name "Group1" when you choose Search Directory, but the floating dialog box that shows off to the right of the entry shows the single user's information and email. I'm assuming this is why it's getting sent there?
I did turn on "exhaustively check all address books" setting and can get the Ambigious name dialog to pop up, from which I can select the group I'm intending on sending the message to... but is this a workaround that everyone will have to do? It seems that the lookup is confused and will keep reverting to the first match it finds which is the User's listed in the person view... and ignores the group name in the group view.
Feedback response number WEBB85RJ9E created by A Cross on 05/24/2010