P: Tags & whitespace handling inconsistent

Using Lightroom 4.1 on Mac.I usually tag pictures, which show people with the names of the people.For this I manually set up a hierarchy like "People/John Doe". Now I select a picture, press cmd+k to enter the "add keyword" mode. Now I enter the person's name. In this case John. While entering it the autocompletion shows the matching name, i.e. John Doe. I press enter.Lightroom now applies to _separate_ tags called "John" and "Doe" on top level. It should have applied what it suggested, i.e. a single tag "John Doe" which is defined in the hierarchy under People.This bug makes tagging quite difficult because I have to use the mouse for every single picture.