I am getting some very odd behavior after updating to 3.8.
I am running a child theme of Twenty Ten. I'm running 4 plugins: Akismet, AutoExcerpt Everywhere, Random Text, and WP Super Cache. (See #5 below, yes I inactivated all of them eventually.) This site configuration has been together and working fine since late winter 2012--nearly two years. http://halfoftheholylife.org
(1) (Most annoying.) My base url opens a specific (and rather old) post, not the front page that aggregates all the most recent posts. It does this in Safari, Firefox, Chrome, and Opera. The browser address line shows only the base url, but the title up at the top of the browser window shows the post title. Emptying the cache changed this in Chrome, but after I closed and reopened Chrome the problem was back. I've tried re-saving Permalinks--no help. I've looked for the place in Settings where one specifies posts or a static page--not there. The annoying new "Customize" feature already had "Your latest posts" chosen, but I resaved it with that choice anyway. This fixed the problem in Safari, but not the others. And when I logged out of my site, the problem was back in Safari. too!
(2) The admin bar that shows at the top on the public side when logged in was missing for a long while (while I was going back and forth, editing a post). There was no "Edit" link at the end of the post I was working on, either. Yet the back button on Safari got me back to the edit window just fine. Then, the bar reappeared, along with the "Edit" link.
(3) I added new tags to the post, but the tag cloud (in footer) did not update. I clicked "delete cache," no change. I re-saved the tag cloud widget. I went to settings and turned WP Super Cache off, then on again. I manually deleted the cache, did a preload--no change to tag cloud.
(4) When I turned WP Super Cache off, the "delete cache" button disappeared from the admin button across the top. When I turned it on again, that button did not reappear, though the bar remained there.
(5) I deactivated ALL of my plugins. No update to tag cloud. And that one rather old post showing when browser is pointed to the base url--or when site title clicked--or when return to site chosen after log out.