"By Hand" button in "Lookup Activity" dialog not working?

I've noticed something lately that I'm pretty sure worked differently a while back. If I scan for an item that is not found and get the "Lookup Activity" dialog box, the action of the "+ By Hand" button now simply removes the unfound item from the dialog. I'm pretty sure it used to pull up the new item search/entry dialog box before. (I think that would be the desired effect.)

Can someone let me know if this is a bug or the currently desired effect. If it is the desired effect then what is the difference between the "+ By Hand" buttons and the "X Clear" button on the Lookup Activity dialog?

Thanks for any help,
Leonard Armstrong