I don't think you can move that '+' in between Tabs.

If you want to open a New Tab to the right of a Tab you're currently on, type in the URL box this:

About:Config

Then enter this in the Config Search Box:

browser.tabs.insertAfterCurrent 

Only that preference should come up. Double-Click on it to change the 'false' value to 'true'. It may not take right away, so you may want to Exit the browser and start it again for the new behavior to take place.

~Pj

Maybe I was not clear enough. I want the + to the right of the rightmost tab like the older versions had it.

Hi rtsender, although it shows as being further to the right on the Customize page, the + should slide over next to the last tab when you exit Customize (Customize Firefox controls, buttons and toolbars).

If it doesn't, is there anything in between that might be interfering?

If all else fails, there's a button at the bottom of the Customize page labeled "Restore Defaults" which will roll back the toolbar area layout to the default. You then can re-customize the other areas and avoid touching the + button.

jscher2000 said

...Although it shows as being further to the right on the Customize page, the + should slide over next to the last tab when you exit Customize (Customize Firefox controls, buttons and toolbars).

I couldn't move it. Makes sense, because the 'right-arrow' scroll button is next to the Tab in view.

~Pj