Drop down in the Date search criteria of the Issue nav closes pretty quickly on Firefox

In the Issue Navigator, the Minutes, Days, hours drop down present in the the Date Search Criteria closes immediately after it is opened.

Steps to Reproduce:
1. Navigate to Issue nav.
2. In the Basic search mode, click on the More Criteria to add a Data search field like Due Date, Updated Date, Resolution Date, etc
3. In the search criteria click on the Minutes, Hours, days dropdown.

Workaround is to click and hold the dropdown.

See this video for more details -> http://screencast.com/t/E8TnunSzBLh

As of 1de9dff, DateSearcher.js wraps all inputs in a <label>. This means that clicking an input focuses the radio button — this is particularly noticeable in Firefox where you must double click to focus an input (see attached video).