Tabs open at end in firefox

When I installed ubuntu 10.04 firefox started to open new tabs not at the end (where i can find them easily) but after the tab I was working.

"Reclaim" your new tab at end of the tabs by
....
If you don’t want new tabs to be affected, go to
about:config
(see http://kb.mozillazine.org/About:config for more info)
and make false (by double clicking it) the preference
browser.tabs.insertRelatedAfterCurrent
...
(maybe other versions of firefox have something like this so find it by yourself)