So lately, I've been noticing on one of my macs that Safari behaves a slight bit strangely. Whenever I have a window open with a single website (no additional tabs opened), Safari likes to act like there are tabs anyway: Note the single tab on the upper left. I can even grab this single tab and "split it off" into another window if I want, though when I do that, the "old" window disappears. On my other macs though, Safari acts normally when I don't have multiple tabs: Other than this glitch, Safari seems to be running okay on the affected mac. Still, it's enough of an oddity that I'm wondering if anyone else has run into this? I've rebooted (a few times), and repaired permissions, and for whatever reason it's still coming up this way.