Hi

I should be able to help you with this.

1. In Firefox, type about:preferences into the address bar and select the General tab on the left had side.
2. Towards the bottom of that page, you should see a section labelled Tabs.
3. Tick the box next to When I open a link in a new tab, switch to it immediately.

This should help, but if not, please come back here and we can look into a different solution for you

I also found that clicking on "Alt-T" for "Tools" then clicking "Options" goes to the same page. The thing that confused me was the web page look rather than the old tools page look.

Note that you can hold the Shift key when you click a link with the moue to toggle the effect of setting focus the the new tab.

The shift-key & click option brings up a whole new Firefox window not just a tab & then switching the focus to that tab.

Holding Shift this way only works for links that you force to open in a tab/window, so you need to hold Ctrl as well (Ctrl+Shift) when you left-click the link or hold Shift middle-click the link.