gtk file-chooser: Autocompletion - Dropdown-list: selection fails

1) Ubuntu 12.04, all updates till date.

2 ) libgtk-3-0 3.3.20-0ubuntu1

3) I open a file-open dialog, press a key on keyboard to start typing in location bar. When I write my path to the file I want to reach, the autocompletion dropdownlist begins to work. I see the file I want to open in the dropdownlist.
I select it with either the keyboard or the mouse, and the path to it gets written in the location bar. I click the open button or press return to open it.

4) I open a file-open dialog, press a key on keyboard op to start typing in location bar. When I write my path to the file I want to reach, the autocompletion dropdownlist begins to work. I see the file I want to open in the dropdownlist.
BUT when I try to select it (regardless if mouse or keyboard used), the selection is GONE and nothing stands in the location bar! The autocompletion dropdownlist changes its content to the folder I started off . But even there I do not see anything written into location bar, when I select an item in the list.

So I have so start over again and click me throu the folders to get there, or just autocomplete folders and files seperately (which works, using the location bar only and forget about the dopdownlist) -- verry annoying...