While I understand that your experiencing the opposite, what is the same is that after a fresh install that option does not work in the way that you mentioned.
I can confirm this as a bug and reproduce it. To reproduce: 1) Freshly install or upgrade Firefox 2) Click Edit > Preferences on the menu 3) Click on Tabs... 4) Observer the "New pages should be opened in:" option If Firefox is performing the opposite then what is selected you must 5) Select the opposite option 6) Close the preferences 7) Reopen the preferences (step 2) 8) Choose the desired option 9) Close the preferences again >From this point on Firefox should perform your desired option . ** Changed in: firefox (Ubuntu) Importance: Undecided => Medium Assignee: ChrisBurgan => (unassigned) Status: Needs Info => Confirmed -- Firefox doesn't display new windows in new tabs despite option being set https://launchpad.net/bugs/75758 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs