If any of you have been driven nuts by having alert boxes with "Please log in and try again" and entire popup windows ready for the login then the chances are you are developing using a laptop.
The culprit is, I believe, in LeftAndMainPing.js where the site is ajax pinged (or simply ajaxed) in the background to keep the session going. The snag is that with some devices, like my laptop, the net connection is not available 100% of uptime. Once it fails the popups pile up bigtime which is a huge irritation.
1. Ping 188.8.131.52 (google's dns) to see if there's a net connection before attempting the connection to login status. However this is cross site requesting which is not favoured.
2. Use the window.navigator.onLine property supported by browsers. I am trying this right now and will report.