By tabs on bottom, I mean beneath the address bar, not at the bottom of the screen. That was the original design of Netscape then Firefox and you had your choice with an easy change with about:config. Now to continue to have it look that way, you have to be a programmer (which I am not) to write code for the userChrome CSS file. It all just sucks.
Sorry, my bad as I thought you meant the tabs were at the bottom of the page. Mine have always been at the top just below the address bar which is the way I prefer it.
So far, it is working out and pages that used to freeze before the update no longer freeze up.