My problem is that I don't get the linked page at all. Instead I get two duplicate tabs of the page where I middle-clicked the link.

I agree with G_Mann https://support.mozilla.org/en-US/questions/998920 about FF29.

I am using the addon https://addons.mozilla.org/firefox/ad.../classicthemerestorer/. It solves most of the problems, not this one. I have not found an extension to fix this part of the total mistake called a "Security Update". I did not have this problem until then.

That sounds even worse than my problem. I used to always right-click and select open in a new tab. My brother wanted me to get used to the middle mouse button for efficiency, but Firefox has put an end to that.

That is a good post (G_Mann). I agree with him. I don't find it that hard to figure out things, but there are a few. For example, how do you access the Downloads tab? It seems to be back in 29.0.1 (if you know how to access the "secret" menus with F10/Alt), but I could've sworn it was nowhere to be found in 29. Then again, I just remembered Ctrl + J and went with that.

For me, I have let a lot of the annoyances go just because I have faith in Mozilla. I've liked Firefox ever since it was called Netscape! And I have fought off Chromers at every turn. But now, who am I kidding?

It might be you are holding the middle button down too long. Or the mouse itself my be the problem.

Please don't reply anymore. If you don't want to read the OP, then you shouldn't reply. Thanks.

I just switched to SeaMonkey. It is an internet application suite that replaced the Mozilla application suite. Has browser, email, etc. all in one. Forked from Firefox, Thunderbird, etc. Fewer of the add-ons work than in FF or TB but the middle-click to open link in new tab still works and the other options that they removed from FF still work also. It can be found here: http://www.seamonkey-project.org/ .

I had this problem myself; may i ask if you are using a R.A.T. (any of the serie) mouse? I tested the clicks and found out it was a hardware problem related to dust and dirt on the wheel's clicking contact point. Just had to open the device and blow on it and it fixed this issue that drove me crazy (I thought it was a mozilla issue so i tried seamonkey, icewisel etc..) for 2 weeks. It may apply to some other mouses.

Thanks for the replies. An update since then has actually fixed all the problems but one. Now I'm trying to get the downloads to open in a tab but only an extension seems to fix that...

I was using "Duplicate This Tab" and "Middle Click to Go Back". I unchecked middle click to duplicate this tab in preferences of Duplicate This Tab. This solved the problem in Middle Click To Go Back. I was using the right mouse button and context menu to open link in new tab.

After awhile I forgot and clicked middle button to open link and it worked correctly so I guess that update fixed it, and CTRL+SHIFT+U still duplicates the tab.