ASP.Net ReportViewer - Cannot hide the document map
===

I have an .aspx page that contains a `ReportViewer` control. The report displays properly, but I cannot get the document map to disappear. If you look at the two following images:

![Doc map expanded][1]
![Doc map collapsed][2]

You can see that the toggle button exists, but when I click it nothing happens. I also tried this in chrome with the developer console enabled and there were no javascript errors.

Any thoughts on what I may need to do to fix this issue?

  [1]: http://i.stack.imgur.com/OIzGI.png
  [2]: http://i.stack.imgur.com/DRQAG.png