Hmm, why would that happen. One possibility is that those sites are launching it as a popup. Firefox's popup blocker usually blocks those, unless they were triggered by an action you took in a page such as clicking a link or button. Another possibility is that one of your add-ons is opening it for some reason. ?? Worth investigating, I think. Here's how: You can view, disable, and often remove unwanted or unknown extensions on the Add-ons page. Either: * Command+Shift+a (Windows: Ctrl+Shift+a) * "3-bar" menu button (or Tools menu) > Add-ons * type or paste '''about:addons''' in the address bar and press Enter/Return In the left column of the Add-ons page, click Extensions. On the right side, find the "Manage Your Extensions" heading. ''If there is at least one extension before the next heading -- "Recommended Extensions" -- please continue:'' Then cast a critical eye over the list below that heading. Any extensions Firefox installs for built-in features are hidden from this page, so everything listed here is your choice (and your responsibility) to manage. Anything that mentions shopping, coupons, or search, or looks suspicious, or that you just do not remember installing or why? If in doubt, disable (or remove). For your privacy and security, don't let mystery programs linger here. Any improvement? '''If your Add-ons page is blank or is blocked, you can restart Firefox in its Safe Mode to do the above review:''' In its Safe Mode, Firefox temporarily deactivates extensions, hardware acceleration, and some other advanced features to bypass issues that can cause problems with pages. ''If Firefox is running:'' You can restart Firefox in Safe/Troubleshoot Mode using either: * "3-bar" menu button > Help > Troubleshoot Mode... (before Fx88: Restart with Add-ons Disabled) * (menu bar) Help menu > Troubleshoot Mode... (before Fx88: Restart with Add-ons Disabled) and OK the restart. A small dialog should appear. Click the Open button (before Fx88: "Start in Safe Mode" button). ''If Firefox is not running:'' Hold down the option/alt key when starting Firefox. (On Windows, hold down the Shift key instead of the option/alt key.) A small dialog should appear. Click the Open button (before Fx88: "Start in Safe Mode" button). ''Note: Don't use the Refresh without first reviewing this article to understand what will be deleted:'' [[Refresh Firefox - reset add-ons and settings]]. Anything interesting in there?