Screen shot of your settings?

Google settings.

Hi, Firefox's internal setting diverts new windows to new tabs automatically, so you'll need to switch that, too. It's on the Preferences page:

• Mac: "3-bar" menu button (or Firefox menu) > Preferences
• Windows: "3-bar" menu button (or Tools menu) > Options
• Linux: "3-bar" menu button (or Edit menu) > Preferences
• Any system: type or paste about:preferences into the address bar and press Enter/Return to load it

In the search box at the top of the page, type tab and Firefox should filter to the "Tabs" section.

Uncheck the box for "Open links in tabs instead of new windows"

Does that fix it?

Firefox has a setting to redirect a link to open in a tab instead of a window.

• Options/Preferences -> General -> Tabs: Open links in tabs instead of new windows

Already unchecked and still opening in tabs. On two different computers too.

I can't think of a good reason for that setting not to work. Do you use any extensions related to tabs that might be doing the diversion?

For people who are allergic to tabs and never, ever want a page to open in a tab, I created an add-on to pop new tabs out into their own windows. Might be too drastic for you: https://addons.mozilla.org/firefox/addon/i-hate-tabs-sdi-for-firefox/