Hello, jusara.

I'm sorry to hear you've been experiencing issues with opening new tabs on Firefox and apologize for the wait time you had to go through.

Luckily, I think I may have found a solution to your problem! First, go to Edit -> Preferences -> Tabs and make sure that the When I open a link, switch to it immediately option case is not checked.

This should normally make your browser open new tabs and not switch to them immediately, whether you open the new links with the scrolling wheel button, or any key shortcut.

Should this answer have resolved your current issue, please mark it as such or let us know the result in a comment reply and we will be glad to assist you further.

Thank you for all your interest in Mozilla and have a wonderful day!

If you choose the standard setting for clicking with the mouse wheel then Firefox should work properly with clicking the mouse wheel.
There is no need to set special keyboard or click action.

Thank you for the response. I took a look, and that box is not checked. It must be something else.

I do not know what the standard setting is. In my Mac system preferences, when I access the Logitech Control Center, I click on "wheel button" (button 3), and get a drop down menu with the following choices:

Nothing
Click
Advanced Click
Cruise
Horizontal Scroll
Keystroke
Modifiers
Open Application
Open Document
Open Folder
Open Web Page
Back
Forward
Cover Flow
Display Control
Eject CD
End Session
Expose' Dashboard & Spaces
One-Touch Search
Quick Look
Screen Capture
Sound Control
Switch Application
Zoom

I'm lost here. The mouse used to do it, then I needed to unplug it, and when I set it up again, the wheel button is inert when used on a link.

Hello again, jusara.

I'm sorry again you haven't been able to resolve the issue just yet. From the new information you have just provided, it sounds to me like the problem would be tied to the driver software managing your mouse and not Firefox itself.

You may want to try to set your wheel button (button 3) to Click and Advanced Click and see how that goes.

As always, please let us know how it all goes as we will be waiting for your verdict.

I have tried this, and when I use the wheel button to click on a link, absolutely nothing happens. I've also downloaded the software for the mouse and re-installed it- still nothing. Perhaps I should just get a different mouse.

Hello again!

You may want to forward the issue to the Logitech customer support and otherwise reinstall the Logitech software again or reset the driver software to factory defaults, since I am not sure anymore that the problem resides within the web browser itself.

If all above fails, try and see if you can get the mouse to work propely on other computers running the same version of Mozilla Firefox.

I finally figured it out!!!

Re-loaded the logitech software (unnecessarily), and on the wheel button chose advanced click.  Below, under 'configure advanced click', I chose triple click, and in the modifier selection, chose the 'command' option.  Of course the button number was 3.  Don't know if the modifier selection was necessary- but I'm not going to test it and perhaps mess it up again.

 Thanks again!