this happened to me too, after getting a new mouse. Goto Control Panel...Mouse and set your wheel button to Middle-Click

The problem is not with Firefox. It's a matter of setting the Mouse properties. So Control Panel is indeed a good place to start. Thanks, all.

Laral, hate to break it to you, but that is false. After updating firefox on two computers (one a laptop with a perfectly functional middle-button built in that worked fine) this functionality no longer worked on either computer.

before update, it worked fine. It *still* works fine outside of firefox. However, inside of firefox I can no longer click with my middle-mouse button on either computer to open a new tab. ctr-click still works, but this is.... less convenient.

Joe, it's NOT a Firefox thing. It's Windows. Honest. Please, go to your Control Panel, select the Mouse, and find the option to control the center mouse wheel. Please report the results.

Well, for OS X on a Mac, it does appear to be a "firefox thing." Same mouse, same system, same OS version, new Firefox. Only firefox changed. Only firefox appears to insist on opening all clicked links (mb2 or mb1) in a new window. (Even though "preferences" says open in a new tab. I can only open a link in a new tab by using MB3 and selecting "Open Link in New Tab." -- it is a good thing that that is the first option ;) )

reposting a new thread as there's an issue on FF6

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I had the same problem, and thought it was due to my Tab Mix Plus add-on, but then I found out that it was due to Greasemonkey. The Sept 6th Greasemonkey update (version 0.9.11) fixed the whole problem, you can download it here: https://addons.mozilla.org/en-US/firefox/addon/greasemonkey/versions/

Hey Shebally, I have the same problem, I use Tab mix plus as well and Greasemonkey. I just installed the gm update but it's still there. The middle wheel reacts real strange. I can still close tabs with it, I can still open favourites in new tabs. But when I try to open a link nothing happens. Neither does ctrl click.

Any help appreciated

This was solved long ago, thanks to all who responded. In my case, with a Logitech cordless mouse and keyboard, I had to use the Logitech software to get the middle mouse wheel to behave like I wanted it to.

So much for those who claim it was a mouse issue, not a Firefox issue. I also had the problem, it started when I did a Firefox upgrade, nothing else changed, not the mouse, not any other software, nothing. The problem then went away, no mouse change, no other software, I didn't even change my sox, only thing that changed was another Firefox update and hey presto wheel clicks back acting correctly.

You can't tell me that it was not a Firefox issue.

For all those who have currently the same problem as described by user splungedude, try updating greasemonkey -- it fixed the problem in my case, which was NOT related to any mouse settings. I'm surprised it didn't work for splungedude though, since his description was exactly the same as my problem.

Anyway, thanks to shebally for the hint to greasemonkey.