Steps to reproduce: 1. Open in new links (in bugzilla) "Home" and "Search". 2. Switch tabs and switch back. 3. Open "Help" in new link. Result: The "Help" tab should be to right of "Search" tab, not to the left of "Home" tab. This appears to have originated from bug 465673 and makes tab placement unpredictable if you switch tabs often.

Upon selecting a tab, the tabs spawned from opening links in a new background tab will open sequentially to the right of the tab starting from its immediate right. Once the user switches the selected tab, the ordering starts again from the tab's immediate right. This rule is always maintained, and the behavior is predictable. Changing this behavior would mean that, as a tab's hierarchy gets deeper, tabs might be spawned far to the right of the selected tab and its other child tabs or even grandchild tabs, even when tabs had been switched around many times. This is unwanted, because it requires that the user remembers an invisible, complex tab hierarchy and the ordering of many previous user actions in order to understand and predict the placement of a newly spawned tab.