A customer noticed that the "AdminCentral" button in the Main Bar sometimes stops to work, giving a JS error.
These are the steps to reproduce it:

1) Open a IE8/FF browser in a new browser window (A)
2) Clean all browser history / data
3) Point directly to this url: http://demo.magnolia-cms.com
4) Provide username / password
5) Open (double-click) the demo-project page. It opens a new browser window, (B)
6) Now close the (A) window
7) Click on the AdminCentral button.

– JS error (javascript.js)

In Firefox, you obtain the same behaviour opening (drag&drop outside browser app) the B window in a new browser window.