Three choices -- there are more

1) Put tabs on the bottom , where they belong

2) go into customize "Alt" > View > Toolbars > Customize then drag the [+] sign from the Tabs bar to the Navigation bar where it is better suited except when the tabs bar is the only toolbar shown (as mine is in Full Screen mode.

3) get used to using Ctrl+T

Sorry should have read "tabs bar" not "tags bar"

Tabs are on the bottom. There is no "tags bar" that I can find. If I could go back to 3.6.18, I would. v5 downloaded and installed involuntarily, and I am afraid FF may have passed its prime as a browser. Chrome?

Man, this version is BUGGY!!! I just restored default set on toolbars, re arranged the whole thing AGAIN, clicked Done, clicked "Tabs on Top", the "+" reappeared, clicked "Tabs on Top" again, and the tabs are now where I want them with the "+" in place.

We are talking one HECK of a buggy browser. Is there any way to reinstall 3.6.18. versions 4 & 5 just SUCK, sorry to say......

I think I found the solution, the New Tab button cannot be placed to the left of a button added by an extension ("Tabs Count", in my case) it must be next to list-all-tabs or the tab-close button or a tabs strip boundary. You can make an exception by placing one of the space wasters (flexible space, space, separator) to the left of the New Tabs button; otherwise, it will disappear once you leave customize if tabs are on top (even if you have a menu bar above).

The reason is that when the Tabs Bar is on top within the Windows Title Bar all empty space belongs to the title bar so you can move the window around, double click and whatever else you should be able to do with the Title Bar (except see a title).

New Tab button is too wide (twice as wide) for my use on the tabs strip and while it would be nice to have it on the tabs bar when I'm in Full Screen mode with only the tabs bar showing, I can't stand the limitations, it will reside on my Navigation bar as before. And using Ctrl+T is not a big deal, wasted more time on this than than if I used the Ctrl+T for the next five years without a new tab button at all -- even if holding my lap-top with my left-hand.

Another problem I notice is that the new tab button is also disappearing now when tabs are below and think this one might be that I do not allow tabs to scroll horizontally (with a user style) the button disappears so when the tab strip is filled up, which is all the time, the New Tab button disappears. My user style is

• Tabs Bar Minimal Size - Themes and Skins for Browser - userstyles.org
  http://userstyles.org/styles/9043

Totally confused now... I have regained the little "+" box next to the open tabs now, but the "Open New Tab" icon is no longer available on any toolbar. Maybe it's one or t'other.

I think the Ctrl + "T" shortcut is perhaps the best solution. But the Firefox "buginess", after years of easy/smooth functionality, is dismaying.

See the new addition to my last comment. I dislike horizontal scrolling of tabs or multiple rows of tabs, and prefer that they squash down but if the tabs fill up the tab bar then want to scroll but I don't let them then the "New Tab" button disappears even with tabs below, unless moved next to one of Mozilla's own buttons at the right of the tabs bar.

You can find the New Tab button showing as a '+' on the Tab bar.

You can open the Customize window and drag the New Tab button that shows as a plus sign (+) from the Tab bar on another toolbar and it will become a regular toolbar button like the New Tab button that you have in Firefox 3 versions.

• Open the Customize window via "View > Toolbars > Customize" or via "Firefox > Options > Toolbar Layout"

If you can't find the New Tab button then click the "Restore Default Set" button in the Customize window.
See also:

• http://kb.mozillazine.org/Corrupt_localstore.rdf

If you want the New Tab button at the far right end of the Tab bar then place a flexible space to the left of it.

• New tab toolbar button: https://addons.mozilla.org/firefox/addon/new-tab-toolbar-button/

New Tab button was not available, and not to be found in the Customize window. It magically re-appeared after I fiddled with the toolbars for a half hour, including a total reset to default, a giant PITA. Very buggy version.

I just hope everything stays the way I have it set up, as various buttons have vanished completely on their own a couple times. Seems stable today. I have it back almost the way it looked in v. 3.6.18, the last stable FF version. Mozilla's ergonomic layout enhancements, weren't.