Firefox normally shows autocompletion entries in the address bar when you start typing a URL (say, gi). Until recently, I was able to select the appropriate entry (e.g. github.com) with my touchpad/mouse, and it would navigate there. However, I recently set up a new laptop (same OS, Ubuntu 14.04, Firefox 33), migrating my firefox profile over, and now it does not do that anymore, and instead searches for the truncated URL (in the above case gi) via google!
Selecting an autocomplete entry with cursor keys and enter works as expected.
Is this a new bug in Firefox, or is this some setting I have to adjust? How can I get the old behaviour back?
Turns out this was caused by an old/deprecated extension, Delicious Bookmarks, which apparently was left over in the profile folder I migrated. Disabled that, now everything works again. :-)