Use these steps to remove data from a drop-down list:

1. highlight an entry in the drop-down list with the mouse or cursor Down key
   do not click the mouse or press the Enter key
2. press the Delete key (on Mac: Shift+Delete) to delete the highlighted entry

There are two prefs related to auto-fill on the location/address bar that you can inspect and modify on the about:config page.

• browser.urlbar.autoFill
• browser.urlbar.autoFill.typed

You can open the about:config page via the location/address bar. You can accept the warning and click "I'll be careful" to continue.

• http://kb.mozillazine.org/about:config

The solution offered is a handy way to remove unwanted addresses but the root of the problem is that if your mouse pointer moves within that entire area (address bar and drop down menu), it will focus on a different address and then even if you click on the address you were typing, so as to clear the unwanted address off the screen, it will still go to the unwanted one instead of the one you typed!

Naturally we're likely to have more than one bookmark under each letter of the alphabet so you're still going to have this problem. I think the drop down suggestions should be controlled by clicking, not pressing enter (unless the user pressed the down key on the keyboard to trigger the menu).

I confirm that I'm experiencing exactly the same issue as OP described.

There might be a problem (bug) that Firefox automatically selects the first entry in the drop-down list. Should be fixed in Firefox 36 (currently beta).

• bug 1043584 - Enter/return key opens entries from drop down menu without pressing arrow keys first on FF 31+

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