This took a while to find so I thought I'd post it here...
If you are using CiviCRM in wordpress, and have the "SEO Ultimate" plugin, and its "Open Graph Integrator" module enabled, you may see the following error:
Warning: Missing argument 2 for CiviCRM_For_WordPress::single_page_title() in /home/civicthe/public_html/wp-content/plugins/civicrm/civicrm.php on line 1273
I'm not sure if this causes problems in the backend, but I'm hoping its the cause of some of mine.
Fix: Disable the "Open Graph Integrator" module Install the similar "WordPress SEO by Yoast" plugin instead - it's open graph module does the same functionality but WITHOUT the error.
I hope this helps someone.