STEPS TO REPRODUCE: 1. Load about:sync-tabs. 2. Disable all network connections. 3. Reload your "about:sync-tabs" tab. ACTUAL RESULTS: The reload completes almost instantly, but it clears everything, resulting in a blank page except for the "Tabs from Other Computers" heading. EXPECTED RESULTS: It should show the most recently aquired tabs data. (i.e. the reload shouldn't change what's shown)
about:sync-tabs has been deprecated. Better synced tabs UI has been implemented in a menu panel (bug 1201331) and sidebar (bug 1210586).