The Ask Toolbar is causing that in the Firefox 3.6.13+ versions. Uninstall that extension. There are a couple of places to check for the Ask toolbar: * Check the Windows Control panel for the Ask Toolbar - http://about.ask.com/apn/toolbar/docs/default/faq/en/ff/index.html#na4 * Also check your list of extensions, you may be able to uninstall it from there - https://support.mozilla.com/kb/Uninstalling+add-ons