The page http://jira.atlassian.com/secure/Dashboard.jspa includes a <Log In> link in the top-right corner. Clicking this link brings you to the page http://jira.atlassian.com/secure/Dashboard.jspa?os_destination=%2Fsecure%2FDashboard.jspa, which again has a <Log In> link. Clicking this link brings you to the page http://jira.atlassian.com/secure/Dashboard.jspa?os_destination=%2Fsecure%2FDashboard.jspa%3Fos_destination%3D%252Fsecure%252FDashboard.jspa. In other words: Jira produces ever longer URLs and directs the browser to a new page each time (different URLs --> different page, as far as the browser concerns).

This issue is not a problem in day-to-day use, but it is a problem for some site crawlers: these tend to get stuck in the Jira web interface as it keeps producing new pages. This creates an unnecessary burden on sites running Jira. Hope you can fix this soon.