Hmm, it doesn't look like that use case works either - i.e., opening a website first, and then choosing the matching login. I tried a random sample of about 6 sites and did not have any luck. Some sites are generally finicky with logins, so it's hard to say definitively, but certainly Open and Fill is not working with AdBlock Plus. I hope this helps. Please let me know if I can test anything specific/further for you.