In JIRA 6.0.6, after clicking on the gear icon next to the issues in Assign To Me gadget, it directs the user to a raw XML page, as the screen-shot attached.

Steps to produce:

1. Create few issues and assign it to your user account
2. Go back to the dashboard, and check the issues in the Assigned To Me gadget
3. Click on the gear icon next to any issue.