Edit mode: selecting one vertex => linked edges not half- higlighted anymore


Using Blender 2.66, at some point, I realized that selecting a vertex in edit mode (3D view) doesn’t highlight the beginning of the edges that are linked to it anymore (I mean: the orange highlight that fades away around midway into the edge).
Adding the end vertex of one of those edges to the selection completely highlights the edge as expected, so I don’t think that my geometry is broken (and by the way not seeing those highlights anymore initially led me to believe that I had managed to rip a few things apart by mistake !)
Is there possibly an option or hotkey that I might have activated by mistake? (note that I am a fairly recent user to the tool)

Edit mode, select all, W -> remove doubles (F6 to increase the merge distance if needed).
If that doesn’t work, http://www.pasteall.org/blend/ and http://www.pasteall.org/pic/ and share the link(s).

Thank you for the quick feedback !

Following the steps above has not changed the observed behavior.

The model is available at: http://www.pasteall.org/blend/19989 (just going through the manga character modelling tutorial at CGTuts)
Here are screenshots:

In addition to the above, I opened a new file and checked what was happening with the default cube at the center of the geometry. And there it looks just fine indeed: http://www.pasteall.org/pic/46917

Right. It’s just the way vertex selection shows when you have mirror modifier applied during edit mode. It’s one of the display modes on the modifier header.

That was it indeed - thank you !