Google account not letting me log out.

So I usually develop in FireFox on Mac, but keep Safari (3.1.2 at moment) open for occasional browsing, HackerN, googling, gmailing.

Today I notice that I cannot log OUT from gmail account from the main google.com page in Safari. Clicking "sign out" just refreshes the page. [ Everything like Javascript is turned ON; no add-on ware to Safari. ]

Next I went to Firefox, and I could log in - and then log out, no problem.

But not from Safari. I could track down the cookie and delete, but I'd like first to figure out WHY google should be glitching. Doesn't this strike others as a strange state of affairs? Ever had it in any browser?