No Issue popups on taskboard, planning board, etc.

I recently upgraded Jira from 4.2.4_b591 to 4.4.1. Greenhopper has been upgraded to 5.7.2. On the taskboard (and others) I used to be able to click the issue number and the issue was brought up in a popup. Now the page performs a full refresh to the issue I clicked. This wouldn't be much of an issue, but there is no way to get back. Clicking the back button returns a "confirm submission" browser message which forces a refresh. It's all very odd.