Firefox does not always apply address autocomplete
1) I have 'youtube.com' in places.sqlite, yet Firefox does not use this entry for autocomplete. 2) I type 'youtube.com' in the address bar, I enter the site and get out of it. Then I start retyping "yo", "yout" ... but Firefox does not autocomplete it.
Further info: 1) Firefox autocompletes all other site addresses in places.sqlite as well as the newly typed addresses. 2) Now, it also happens that Firefox can't handle Youtube webpages correctly: when returning to them with BACK button/key, Firefox always displays them at the top of the page, regardless of the last position in the page.
It can't be a coincidence. It seems like Firefox doesn't like Youtube and that's why it doesn't autocomplete the name! :)) I repeat: IT ONLY HAPPENS WITH YOUTUBE.