Can anyone help me with finding the preference in about:config I changed a week ago?

Prefs that aren't the default show as bold on the <b>about:config</b> page. You can click the Status column header to sort by status. That may make it easier to remember which setting you've changed if you can't remember it.<br /> Otherwise you can reset all prefs by deleting the prefs.js file or use the check-box on the Safe mode start window (Help > Restart with Add-ons Disabled). ---- *http://kb.mozillazine.org/about:config *http://kb.mozillazine.org/Resetting_preferences