Ubuntu – Why did the middle mouse button stop working in firefox exclusively

firefoxmousetouchpad

For some reason I'm plagued by especially rare bugs. This time my middle mouse button ceased to work in firefox exclusively. I can use it to copy stuff in terminal or to start another instance of a program clicking on the program's icon on the unity launcher bar.

But I can't use my middle mouse button to open a link in a new tab. That's quite annoying. The button click gets recognized, as the links highlight as I middle click them. A new tab just isn't opened.

I already disabled all addons to firefox to see if it's an addon problem. Turns out it's not. Even purging firefox and reinstalling didn't help.

I own a Logitec MX510 mouse on my HP laptop that also has Synaptics TouchPad. On the touchpad the middle and left button never worked in ubuntu at all (firefox or anywhare else).

Any ideas what could be wrong? What else could I try.

Edit:
Now the problem has reached my work PC as well. After the latest firefox-update (to version 6.0.2): The right mouse button on my work PC (Desktop) does open the context menu, but as soon as I move my mouse even the tiniest bit, the menu closes. So the problems might be related to the 6.0.2 update of firefox or not, but it's certainly suspicious that both PC have mouse problems ins firefox only.

Best Answer

Purging Firefox removes global settings only, not the Firefox profile itself. To check whether it's an issue related to your Firefox profile settings, try creating a new, clean one:

mkdir /tmp/firefox-test
firefox -profile /tmp/firefox-test -no-remote &

/tmp/firefox-test can be removed afterwards. If the problem is persistent, you might want to take a look at your settings in the about:config URL, search for keywords like "mouse", "click" and "tab". Otherwise, you could check the prefs.js file in your Firefox profile folder which is located at ~/.mozilla/firefox/XXXXXXX.PROFILENAME/prefs.js. If you can't get any out of it, quit the Firefox instance using this profile folder and rename / remove this prefs.js file to reset your settings. If this still does not help, export data like your bookmarks and create a new profile using the Profile Manager which can be started with firefox -p.