After I open Firefox I start typing the URL. After each letter I see autocomplete suggestions. Imagine I type "g", then "o" (google is shown as autocomplete), but then I enter "a". Since I have no pages that begin with "goa", autocomplete is hidden and the problem is, I can no longer type anything. All my key strokes are now ignored (backspace, enter... it dosen't matter). But I still see the cursor blinking after "goa". I have discovered that Firefox must be focused on some other interface element (not in the address bar), because if I press the TAB key, the focus is again shifted to the address bar and I can continue typing. Sometimes I have to press TAB 2 or 3 times while entering an address to be able to write what I want. It looks like every time autocomplete is closed, the program focus leaves the address bar. I've been having this problem for at least 4 or 5 versions of Firefox and it does not happen on every Firefox session. It can be solved by closing Firefox and opening it again. Pressing the TAB key has become kind of a reflex, so it's just annoying and I can work around it. But why is this happening?