<p dir="auto">(1) Shrink the page horizontally so the the navbar moves into the drop down. (2) Drop the drop down (3) Leaving the drop down dropped, stretch the page again. (4) Drop the drop down and it produces a nasty scroll bar in the header which you have to scroll down to see the dropped menu.</p>
<p dir="auto">Steps to reproduce:<br>
Open, for example, bootstrap-3.0.2\examples\theme\index.html.</p>
<ol dir="auto">
<li>Make screen smaller to get collapsed nav bar</li>
<li>Click on one of menu for drop-down list in nav bar</li>
<li>Maximize screen again</li>
<li>Go to Drop-down - drop-down and click again -  list will be in scroll area.</li>
</ol>
<p dir="auto">Did the same on tablet Nexus - 7'' : Landscape and Portrait, the same effect. After refresh everything is fine again.</p>